Rapid, application-based survey to characterise the impacts of COVID-19 on LGBTQ+ communities around the world: an observational study

INTRODUCTION

Emerging evidence indicates that the COVID-19 pandemic, and the responses it has generated, have had disproportionate impacts on lesbian, gay, bisexual, transgender and queer (LGBTQ+) communities. This study seeks to build on existing information and provide regional insight.

METHODS

In response, a cross-sectional survey was administered to a global sample of LGBTQ+ individuals (n=13 358) between 16 April and 20 May 2020 via the social networking application Hornet. The survey contained questions that characterise the impact of COVID-19 and associated mitigation strategies on economics, employment, mental health and access to healthcare.

RESULTS

5191 (43.9%) individuals indicated they were somewhat, slightly or unable to meet basic needs with their current income, while 2827 (24.1%) and 4710 (40.1%) felt physically or emotionally unsafe in their living environment, respectively. 2202 individuals (24.7%) stated they are at risk for losing health insurance coverage. 2685 (22.7%) persons reported having skipped or cut meals as there was not enough money.

CONCLUSION

Many LGBTQ+persons who responded reported adverse consequences to mental health, economics, interruptions to care and lack of support from their government. This data is part of ongoing analyses but accentuates the unique needs of LGBTQ+ communities that will require targeted, ameliorative approaches.

Perceived Interruptions to HIV Prevention and Treatment Services Associated With COVID-19 for Gay, Bisexual, and Other Men Who Have Sex With Men in 20 Countries

BACKGROUND

The coronavirus pandemic has necessitated a range of population-based measures to stem the spread of infection. These measures may be associated with disruptions to other health services including for gay, bisexual, and other men who have sex with men (MSM) at risk for or living with HIV. Here, we assess the relationship between stringency of COVID-19 control measures and interruptions to HIV prevention and treatment services for MSM.

SETTING

Data for this study were collected between April 16, 2020, and May 24, 2020, as part of a COVID-19 Disparities Survey implemented by the gay social networking app, Hornet. Pandemic control measures were quantified using the Oxford Government Response Tracker Stringency Index: each country received a score (0-100) based on the number and strictness of 9 indicators related to restrictions, closures, and travel bans.

METHODS

We used a multilevel mixed-effects generalized linear model with Poisson distribution to assess the association between stringency of pandemic control measures and access to HIV services.

RESULTS

A total of 10,654 MSM across 20 countries were included. Thirty-eight percent (3992/10,396) reported perceived interruptions to in-person testing, 55% (5178/9335) interruptions to HIV self-testing, 56% (5171/9173) interruptions to pre-exposure prophylaxis, and 10% (990/9542) interruptions to condom access. For every 10-point increase in stringency, there was a 3% reduction in the prevalence of perceived access to in-person testing (aPR: 0·97, 95% CI: [0·96 to 0·98]), a 6% reduction in access to self-testing (aPR: 0·94, 95% CI: [0·93 to 0·95]), and a 5% reduction in access to pre-exposure prophylaxis (aPR: 0·95, 95% CI: [0·95 to 0·97]). Among those living with HIV, 20% (218/1105) were unable to access their provider; 65% (820/1254) reported being unable to refill their treatment prescription remotely.

CONCLUSIONS

More stringent responses were associated with decreased perceived access to services. These results support the need for increasing emphasis on innovative strategies in HIV-related diagnostic, prevention, and treatment services to minimize service interruptions during this and potential future waves of COVID-19 for gay men and other MSM at risk for HIV acquisition and transmission.

A rare case of native mitral valve infective endocarditis presenting with complete heart block and intermittent atrial flutter

Mitral valve infective endocarditis, without aortic involvement, is a rare cause of complete heart block. It is thought that infections placed close to the conductive system of the heart may drive a conduction block. We found six cases in the literature, via searching PubMed, of mitral valve infective endocarditis with complete heart block and no aortic involvement. We report a case of complete heart block with a junctional escape rhythm in a patient with a Staphylococcus Aureus vegetation on a native mitral valve only.

Pharmacobezoar: An Unusual Cause of Large Bowel Obstruction

Large bowel obstruction (LBO) is an abdominal emergency with high morbidity and mortality rates if left untreated. LBO is four to five times less frequent than small bowel obstruction (SBO) and the causes of LBO and SBO differ substantially. Colonic malignancy remains the most common cause of LBO (> 60%). Additional causes of LBO include entities such as diverticulitis, colonic volvulus, and adhesion. Herein we present a case of acute LBO caused by pharmacobezoar.

Adenocarcinoma of Lung Presenting as Lambert-Eaton Myasthenic Syndrome

Lambert-Eaton myasthenic syndrome (LEMS) is a paraneoplastic neuromuscular junction disorder. LEMS presents with muscular weakness and fatigability, mainly involving the proximal lower limbs. There are 2 types of LEMS depending on the etiology: paraneoplastic and idiopathic. The paraneoplastic form, which constitutes more than a half of the cases, is mostly associated with intrathoracic neoplasms. Most cases are seen in patients with small cell lung cancer; other subtypes of lung cancer are extremely rare. In this article, we report a case of LEMS as a rare association with adenocarcinoma of the lung.

Persistent hematuria caused by renal cell carcinoma after aortic valve replacement and warfarin therapy

Hematuria is a common finding in renal cell carcinoma, and persistent hematuria, even in those receiving anticoagulation, warrants workup. We present a case of a patient with persistent hematuria who was found to have a renal mass that was not evident on renal ultrasound and computed tomography of the abdomen and pelvis but was seen on magnetic resonance imaging.

Lack of Association Between the Clinical Outcome of Clostridium difficile Infection and Current Steroids Use

Background

The purpose of this study was to compare the outcome of Clostridium difficile infection (CDI) in patients on systemic steroids for various indications to patients not on steroids in term of disease severity, and associated morbidity and mortality.

Methods

We retrospectively reviewed records of all patients with CDI at our hospital from January 2011 to December 2016. Patients were evaluated for baseline characteristics, comorbidities, medications, disease severity, disease-related length of stay (LOS) from the diagnosis of CDI to discharge, need for surgical intervention, and disease-related mortality. Based on systemic steroids use, patients who were using steroids for different indications constituted the study population, and those with no steroids use were clustered as a control group.

Results

Of the 258 patients included, males were 127 (49%). Severe and severe-complicated CDI developed in 21/63 (33.3%) and 1/63 (1.6%) of patients on steroids (average daily dose of 20 mg), and in 73/195 (37.4%) and 5/195 (2.6%) of patients with no steroids use (P = 0.56 and P = 0.66, respectively). Surgical intervention was not required in the steroids group and 5/195 (2.7%) of patients not on steroids underwent bowel surgeries (P = 0.38). Mean LOS (days) was 11.6 ± 1.5 in the steroids group and 10.4 ± 0.7 in the no-steroids group (P = 0.4). CDI-related mortality occurred in 9/63(14.3%) of patients on steroids, and in 15/195 (7.7%) of patients not on steroids (P = 0.12; odds ratio (OR): 2; 95% confidence interval (CI): 0.8 - 4.8).

Conclusion

There was no significant difference in the severity of CDI, need for surgical interventions, disease-related LOS and mortality in systemic steroids users compared to patients not on steroids.

Symptomatic Diverticular Disease in Patients With Severely Reduced Kidney Function: Higher Rates of Complications and Transfusion Requirement

Background

The prevalence of diverticulosis is increasing with 5-10% of patients developing diverticulitis and 5-15% developing symptomatic bleeding. Diverticulitis can result in abscess, perforation, fistula, or obstruction. Bleeding has combined morbidity and mortality rates of 10-20%. The purpose of this study was to compare diverticulitis-related complications and transfusion requirements for diverticular bleeding in patients with normal to moderately reduced kidney function (glomerular filtration rate (GFR) ≥ 30 mL/min/1.73 m²) and patients with severe renal impairment (GFR < 30 mL/min/1.73 m²), and identify factors associated with these outcomes.

Methods

We retrospectively reviewed records of all patients with diverticulitis and diverticular bleeding treated at our hospital from January 1, 2011 to July 31, 2016. Patients were evaluated for baseline characteristics, GFR, baseline hemoglobin, medications, comorbidities, length of stay (LOS), presence of perforations or abscesses and the need for transfusion.

Results

Of the 291 patients included, males were 167 (58%). Perforations and abscesses complicating diverticulitis developed in 31/136 (23%) of patients with GFR ≥ 30 mL/min/1.73 m², and in 13/26 (50%) of patients with GFR < 30 mL/min/1.73 m² (odds ratio (OR): 3.4; 95% confidence interval (CI): 1.423 - 8.06; P = 0.0073). Mean LOS (days) was 6.3 ± 4 in the GFR ≥ 30 mL/min/1.73 m² group and 8.5 ± 4.4 in GFR < 30 mL/min/1.73 m² group (P = 0.0001). Blood transfusion for diverticular bleeding occurred in 11/78 (14%) of patients with GFR ≥ 30 mL/min/1.73 m² and in 22/51 (43%) of patients with GFR < 30 mL/min/1.73 m² (OR: 4.6; 95% CI: 1.99 - 10.76; P = 0.0004). Among patients who needed transfusion, mean LOS was 8.5 ± 2.5 in GFR ≥ 30 mL/min/1.73 m² group and 9 ± 5 in those with GFR < 30 mL/min/1.73 m² (P = 0.04). There were no differences in age, gender or race between the study groups.

Conclusion

There was a significant increase in complicated diverticulitis cases, transfusion requirements for diverticular bleeding and LOS in patients with severely reduced kidney function compared to patients with normal-moderately reduced renal function.

Preliminary Radiology Resident Interpretations Versus Final Attending Radiologist Interpretations and the Impact on Patient Care in a Community Hospital

OBJECTIVE

At academic institutions, overnight emergency radiology examinations are interpreted by the on-call radiology resident and are reviewed by an attending radiologist in the morning. The objective of our study was to determine the rate of discrepancies between the two interpretations and the possible effect, if any, on patient care.

MATERIALS AND METHODS

The preliminary reports for 11,908 emergency diagnostic imaging examinations interpreted after hours by residents over a 3-year period (January 2002-January 2005) were reviewed retrospectively for any discrepancy with the attending radiologist's final interpretation. A discrepancy was noted if verbal notification of the ordering physician was required. The medical charts of the cases for which there was a major discrepancy between the two interpretations were reviewed. The discrepancies were categorized as to the effect on patient morbidity. The resident discrepancy rates were also compared with RADPEER data from our institution.

RESULTS

The overall major discrepancy rate was 2.6%. This rate is comparable to RADPEER data, which found a misinterpretation rate of 2.1%. The technique most commonly involved in cases with discrepant interpretations was contrast-enhanced CT of the abdomen and pelvis, with the most common diagnosis related to acute appendicitis (total of 21 cases). The rate of discrepancy was highest for residents who were in their third year of training. The indications for these examinations varied; however, the effect on patient management was no significant effect in 92.8%, some negative effect in 6.9%, and significant negative effect in 0.3%.

CONCLUSION

The results of this investigation highlight the minimal discrepancy rate that occurs with overnight resident coverage. Thus, there is no detrimental effect on the quality of patient care from relying on preliminary interpretations made by radiology residents.

Effects of risedronate treatment on bone density and vertebral fracture in patients on corticosteroid therapy

Men and women (n = 518) receiving moderate-to-high doses of corticosteroids were enrolled in two studies with similar protocols and randomly assigned to receive either placebo or risedronate (2.5 or 5 mg) for 1 year. All patients received daily calcium supplementation (500-1000 mg), and most also received supplemental vitamin D (400 IU). The primary endpoint was the difference between the placebo and active groups in lumbar spine bone mineral density (BMD) at 1 year; changes in BMD at other sites, biochemical markers of bone turnover, and the incidence of vertebral fractures were also assessed. In the overall population, the mean (SE) lumbar spine BMD increased 1.9 +/- 0.38% from baseline in the risedronate 5 mg group (P < 0.001) and decreased 1.0 +/- 0.4% in the placebo group (P = 0. 005). BMD at the femoral neck, trochanter, and distal radius increased or was maintained with risedronate 5 mg treatment, but decreased in the placebo group. Midshaft radius BMD did not change significantly in either treatment group. The difference in BMD between the risedronate 5 mg and placebo groups was significant at all skeletal sites (P < 0.05) except the midshaft radius at 1 year. The 2.5 mg dose also had a positive effect on BMD, although of a lesser magnitude than that seen with risedronate 5 mg. A significant reduction of 70% in vertebral fracture risk was observed in the risedronate 5 mg group compared with the placebo group (P = 0.01). Risedronate was efficacious in both men and women, irrespective of underlying disease and duration of corticosteroid therapy, and had a favorable safety profile, with a similar incidence of upper gastrointestinal adverse events in the placebo and active treatment groups. Daily treatment with risedronate 5 mg significantly increases BMD and decreases vertebral fracture risk in patients receiving moderate-to-high doses of corticosteroid therapy.

Risedronate therapy prevents corticosteroid-induced bone loss: a twelve-month, multicenter, randomized, double-blind, placebo-controlled, parallel-group study

OBJECTIVE

Risedronate, a new pyridinyl bisphosphonate, is a potent antiresorptive bone agent. This study examines the safety and efficacy of daily, oral risedronate therapy for the prevention of corticosteroid-induced bone loss.

METHODS

This multicenter, randomized, double-blind, placebo-controlled, parallel-group study was conducted in 224 men and women who were initiating long-term corticosteroid treatment. Patients received either risedronate (2.5 mg or 5 mg) or placebo daily for 12 months. Each patient also received 500 mg of elemental calcium daily. The primary outcome measure was the percentage of change in lumbar spine bone mineral density (BMD). Secondary measures included proximal femur BMD and incidence of vertebral fractures.

RESULTS

After 12 months, the lumbar spine BMD (mean +/- SEM) did not change significantly compared with baseline in the 5-mg (0.6 +/- 0.5%) or the 2.5-mg (-0.1 +/- 0.7%) risedronate groups, while it decreased in the placebo group (-2.8 +/- 0.5%; P < 0.05). The mean differences in BMD between the 5-mg risedronate and the placebo groups were 3.8 +/- 0.8% at the lumbar spine (P < 0.001), 4.1 +/- 1.0% at the femoral neck (P < 0.001), and 4.6 +/- 0.8% at the femoral trochanter (P < 0.001). A trend toward a decrease in the incidence of vertebral fracture was observed in the 5-mg risedronate group compared with the placebo group (5.7% versus 17.3%; P = 0.072). Risedronate was well tolerated, and the incidence of upper gastrointestinal adverse events was comparable among the 3 groups.

CONCLUSION

Risedronate therapy prevents bone loss in patients initiating long-term corticosteroid treatment.

Effects of calcitonin on animal and in vitro models of skeletal metabolism

During the 40 years since its discovery, calcitonin (CT) has been regarded primarily as an inhibitor of bone resorption and its therapeutic applications have been based on this property. A significant body of literature also indicates additional anabolic effects in animal and in vitro models. In a variety of bone loss histomorphometric models in the rat, CT, especially the salmon species, prevents or retards bone loss. In other species, similar results have been obtained, except in the beagle given human CT, in which a recent study reported increased bone resorption and bone loss. Consonant with the histomorphometric effects in several different species, bone mass (density) measured by a variety of methods increases, reversing the bone loss induced by the model. In related studies of mechanical properties, bone strength is increased by CT except in the beagle study which utilized human CT. In other species, experimentally induced fractures show either accelerated healing or heal normally, and there is no effect of CT to impair healing. Finally, studies of bone formation/mineralization strongly suggest an anabolic effect on cartilage formation, bone matrix synthetic activity, and bone growth. These animal effects are reflected by recent fracture prevention studies in humans. If its anabolic effects are ultimately found to be separable and additive to CT's basic action to inhibit bone resorption, new approaches to osteoporosis prevention, and possibly other treatment situations such as cartilage regeneration, may evolve using novel CT-like molecules.

Risedronate therapy prevents corticosteroid-induced bone loss: a twelve-month, multicenter, randomized, double-blind, placebo-controlled, parallel-group study

OBJECTIVE

Risedronate, a new pyridinyl bisphosphonate, is a potent antiresorptive bone agent. This study examines the safety and efficacy of daily, oral risedronate therapy for the prevention of corticosteroid-induced bone loss.

METHODS

This multicenter, randomized, double-blind, placebo-controlled, parallel-group study was conducted in 224 men and women who were initiating long-term corticosteroid treatment. Patients received either risedronate (2.5 mg or 5 mg) or placebo daily for 12 months. Each patient also received 500 mg of elemental calcium daily. The primary outcome measure was the percentage of change in lumbar spine bone mineral density (BMD). Secondary measures included proximal femur BMD and incidence of vertebral fractures.

RESULTS

After 12 months, the lumbar spine BMD (mean +/- SEM) did not change significantly compared with baseline in the 5-mg (0.6 +/- 0.5%) or the 2.5-mg (-0.1 +/- 0.7%) risedronate groups, while it decreased in the placebo group (-2.8 +/- 0.5%; P < 0.05). The mean differences in BMD between the 5-mg risedronate and the placebo groups were 3.8 +/- 0.8% at the lumbar spine (P < 0.001), 4.1 +/- 1.0% at the femoral neck (P < 0.001), and 4.6 +/- 0.8% at the femoral trochanter (P < 0.001). A trend toward a decrease in the incidence of vertebral fracture was observed in the 5-mg risedronate group compared with the placebo group (5.7% versus 17.3%; P = 0.072). Risedronate was well tolerated, and the incidence of upper gastrointestinal adverse events was comparable among the 3 groups.

CONCLUSION

Risedronate therapy prevents bone loss in patients initiating long-term corticosteroid treatment.

Osteoporosis: the need for comprehensive treatment guidelines

Osteoporosis is a debilitating disease that results in nearly 1.3 million fractures per year in the United States. The cost of treating these fractures has been estimated to be as high as $10 billion per year. These costs are expected to more than double during the next 50 years unless comprehensive programs of prevention and treatment are initiated. Both pharmacologic and nonpharmacologic interventions (eg, diet and exercise) have been shown to have a significant impact on the incidence of osteoporosis, depending on the time of their application. Unfortunately, osteoporosis is often not diagnosed until after fractures have occurred, when it may be too late for treatment to have a major impact. To be most effective, therapy should be started early, before serious bone loss has occurred. Because of its efficacy and relatively low acquisition cost, long-term hormone replacement therapy (HRT) is considered first-line pharmacologic therapy for the prevention of osteoporosis. However, for various reasons, less than 25% of US women who might benefit from HRT are receiving it. Aside from HRT, the only other products approved by the US Food and Drug Administration for the treatment of osteoporosis are salmon calcitonin and alendronate. Several other agents are under development, including sustained-release fluoride and other products in the bisphosphonate class. The development and adoption of early detection programs and treatment guidelines are crucial to help ease the economic burden of osteoporosis. These guidelines should incorporate preventive measures such as diet and exercise, risk assessment through proper screening programs, and the appropriate use of pharmaceutical products. The purpose of this paper is to discuss relevant economic issues associated with osteoporosis and discuss the need for a management algorithm that could be used to more efficiently prevent and treat this disease. We conclude that further modeling is needed to determine which programs and treatments are most cost-effective within each at-risk subgroup. As clinicians better understand the need for preventive care and the advantages of the various pharmacologic therapies, patients with osteoporosis will receive higher-quality and more efficient medical care.

Effects of rigid fixation device composition on three-dimensional computed axial tomography imaging: direct measurements on a pig model

OBJECTIVE

To compare the amount of scatter produced by titanium plates versus Vitallium (Howmedica, Rutherford, NJ) plates. Software was also evaluated to determine its effectiveness in removing the scatter and clarifying the underlying anatomy.

MATERIALS AND METHODS

Miniplating and microplating systems composed of Vitallium or titanium were placed on the nasal and frontal bones of three adult pig heads. A computerized axial tomography (CAT) scan was then performed and a three-dimensional CAT scan was reconstructed using MediCad software (MediCad Inc, Cedar Knolls, NJ). The amount of scatter for each plating system was quantitated using the MediCad software measuring tool. The scatter was removed and the three-dimensional CAT scan was reconstructed to assess the clarification of the underlying anatomy.

RESULTS

No scatter was found with either the miniplating or the microplating system composed of titanium. The Vitallium plates did show significant amount of scatter with the mini, micro, and micromesh system. Removal of the scatter resulted in slight improvement in the anatomic detail.

CONCLUSION

Titanium plating systems do not cause any radiation scatter. The MediCad software system allows removal of the scatter found with the Vitallium plates, which helps clarify the underlying anatomy.

The role of calcitonin treatment in postmenopausal osteoporosis

Synthetic salmon calcitonin (SCT) is a potent antiosteoclastic hormone with adjunctive stimulatory effects on osteoblastic function. It is capable of increasing or stabilizing bone mass in osteoporosis and thereby can lessen the risk of fractures. Treatment doses vary from 100 IU daily to 50 IU three times a week, and the duration of treatment is 2 to 5 years. SCT also exerts an analgesic effect on the skeleton that increases its beneficial effect. Side effects, which do not involve organ toxicity, are common but are usually mild and transient. More severe side effects can be managed by maneuvers such as bedtime dosing, premedication, and temporary dose reduction. Primary resistance occurs in approximately 25% of patients and secondary resistance, usually due to neutralizing antibody formation, in 10% to 20% of patients. SCT is indicated in both early and late osteoporosis and is the treatment of choice in the latter.

Paget's disease and fibrous dysplasia

Many papers were published on both Paget's disease and fibrous dysplasia during the past year. In Paget's disease, evidence for a generalized, probably viral disorder of the skeleton has been adduced, although focal radiologic features dominate the clinical picture. Unusual clinical manifestations were highlighted in several clinical reports. A search for biochemical abnormalities other than increased serum alkaline phosphatase and urinary hydroxyproline levels yielded evidence for secondary hyperparathyroidism in many cases, and also, a confusing array of abnormalities in vitamin D metabolite levels. The application of newer imaging techniques such as computed tomography, MR imaging, bone marrow scintigraphy, and thermography was reported. The year's reports particularly highlighted new forms of effective therapy, including intranasal calcitonin, second- and third-generation bisphosphonates, and gallium nitrate. Finally, the feasibility of joint replacement in arthritic joints secondary to Paget's disease was again documented. Fibrous dysplasia continued to be an enigmatic disorder with no new insights as to etiology. Reports of unusual clinical features, imaging characteristics, bony distribution, and an array of endocrine linkages were prominent. A highlight of the year's reports was the discovery of an increased female sex steroid receptor number of dysplastic cells, and the possibility that sex steroids linked to their receptors may be responsible for the bony overgrowth. Concern was again expressed as to the possibility of malignant transformation of dysplastic lesions and the possible contribution of radiotherapy treatment to sarcoma development.

Cyclophosphamide, methotrexate, and 5-fluorouracil in a three-drug admixture. Phase I trial of 14-day continuous ambulatory infusion

The compatibility and stability at room temperature for up to 7 days of a three-drug admixture of cyclophosphamide, methotrexate, and 5-fluorouracil (5-FU) (CMF) was established permitting the practical delivery of the combination as an infusion in an ambulatory setting. Fourteen patients received 20 courses of CMF administered on a continuous infusion schedule for 14 days of a 28-day cycle. The dose rates were fixed for 5-FU (300 mg/M2/day) and methotrexate (0.75 mg/M2/day). The cyclophosphamide dose was escalated from 25 to 50, 75, and 100 mg/M2/d. Leukopenia and thrombocytopenia were observed in two of five patients receiving the maximal dose of cyclophosphamide. No other toxicities were observed including alopecia, stomatitis or liver function abnormalities. This Phase I trial suggests that the cumulative doses of cyclophosphamide, methotrexate, and 5-FU are comparable to the maximum doses delivered as single agent infusions. Furthermore, when the infusion CMF is compared to the "standard" bolus schedule for CMF, the infusion schedule delivers 116%, 8%, and 350% of the respective three component drugs (cyclophosphamide, methotrexate, and 5-FU).

Etoposide admixed with cisplatin. Phase I clinical investigation of 72-hour infusion

The compatibility of etoposide (VP-16-213) and cisplatin (CDDP) in an admixture solution was established by High Pressure Liquid Chromatography (HPLC) studies in vitro at room temperature. A Phase I dual-dose escalation study of the admixture was subsequently carried out utilizing a 24-hour continuous infusion schedule administered for 3 consecutive days and repeated at 3 to 4 week intervals. Twenty-seven patients received a total of 42 treatment courses. The daily dose rates for VP-16-213 were 50, 75, and 100 mg/m2/day. Cisplatin was delivered at 20, 30, and 40 mg/m2/day for each dose level of VP-16-213. Dose-rate limiting toxicity was observed first at the VP-16 dose of 50 mg/m2/day and CDDP at 30 mg/m2/day. At 100 mg/m2/day for VP-16-213, six of 17 courses were associated with life-threatening leukopenia and four of six patients died with sepsis. All but one of the patients developing severe or life-threatening leukopenia had associated acute renal failure with serum creatinine levels greater than 2 mg/dl. The optimal dose rate of delivery for VP-16 and CDDP administered as a 72-hour infusion admixture is 75 mg/m2/day and 30 mg/m2/day, respectively.

Combined 5-fluorouracil and floxuridine administered as a 14-day infusion. A phase I study

5-Fluorouracil (5-FU) and floxuridine (FUdR) were admixed in a single solution and administered via a central venous catheter on a continuous infusion schedule for 14 days. The Phase I trial design developed for admixture combinations was employed with starting doses for 5-FU at 250 mg/m2/day and for FUdR at 0.075 mg/kg/day. Twenty patients and 28 courses were studied. Dose rate limiting toxicity was pseudoregional enteritis with or without stomatitis experienced by five of ten of the courses administered at the highest dose rates of the admixture components. The simultaneous delivery of the two agents results in a modest compromise of the cumulative dose delivered for FUdR. Previous Phase I studies of single agent 5-FU and FUdR had demonstrated that the optimal dose rates for the individual agents in a 14-day continuous 24-hour infusion schedule is 350 mg/m2/d and 0.125 mg/Kg/day, respectively. The maximum dose rate of 5-FU at 350 mg/m2/day for 14 days is not restricted even with the addition of FUdR at up to 0.1 mg/kg/day. The optimal dose rates for Phase II trails should be as follows: 5-FU, 350 mg/m2/day; and FUdR, 0.1 mg/kg/day.

A phase I clinical trial of combined fluoropyrimidines with leucovorin in a 14-day infusion. Demonstration of biochemical modulation

Two consecutive Phase I trials of continuous infusion 5-fluorouracil (5-FU) or floxuridine (5-FUdR) admixed with leucovorin (LCV) were performed and involved 19 and 24 patients, respectively. The studies were carried out to identify the optimal dose rate of delivery for the two admixtures (5-FU + LCV and 5-FUdR + LCV) administered for 14 days, and to determine if biochemical modulation could be identified. The optimal dose rates for 5-FU plus LCV were 200 mg/m2/d and 5 mg/m2/d, respectively. The optimal dose rates for 5-FUdR plus LCV were 0.075 mg/kg/d and 5 mg/m2/d, respectively. The dose rate limiting toxicity for 5-FU plus LCV was stomatitis and for 5-FUdR plus LCV it was diarrhea. LCV administered as an admixture with either 5-FU or 5-FUdR on an infusion schedule decreases the optimally tolerated dose rates for these two agents to 83% and 60%, respectively. This is achieved with low-dose LCV infusions.

Combined floxuridine and cisplatin in a fourteen day infusion. Phase I study

Twenty patients received 28 courses of 5FUDR (floxuridine) admixed with Cisplatin (CDDP) and administered as a continuous infusion for 24 hours for 14 consecutive days. Pharmaceutical studies of the admixture of 5FU with CDDP and 5FUDR with CDDP demonstrated that only 5FUDR was compatible with CDDP and that the admixture was stable for 7 days. This Phase I study established the optimal dose rate for the individual components of the admixture and demonstrated that CDDP decreases the maximum tolerated dose rate for 5FUDR. The optimal dose rate for 5FUDR is 0.075 mg/Kg/d, and for CDDP the optimal dose rate is 7.5 mg/M2/d. Dose rate limiting toxicity is an enteritis which is radiographically similar to regional enteritis and is related to the 5FUDR. An ancillary finding was a significant decrease in serum magnesium levels in 11 of 13 monitored courses presumably related to the platinum.

Consistent N-myc copy number in simultaneous or consecutive neuroblastoma samples from sixty individual patients

Amplification of the N-myc oncogene is detected in about 30% of untreated neuroblastomas. Amplification is associated with advanced stages of disease and rapid tumor progression. However, it was not known if the N-myc copy number was homogeneous in tumor tissue of an individual patient, or if it changed with time in vivo. Therefore, we have made 66 observations on multiple simultaneous or consecutive tumor samples from 60 patients with neuroblastoma. (a) Simultaneous samples were obtained from different areas of 31 tumor masses from 30 patients: a similar N-myc copy number (1-2, 3-10, or greater than 10) was found in all samples from each patient. (b) Simultaneous samples were obtained from different anatomical sites in ten patients. No difference in N-myc copy number was seen. (c) Finally, 25 patients had two or more tumor samples obtained over time. Thirteen patients had a single copy of N-myc in all samples, and 12 had consistent levels of amplification in all samples. Two of the latter cases had single copy of N-myc in a second-look surgery sample, but no tumor was evident histologically. This study demonstrates that the N-myc copy number in human neuroblastomas is usually consistent within a tumor, not only at different tumor sites, but also at different times in vivo. Overall, these findings suggest that N-myc amplification is an intrinsic biological property of a subset of neuroblastomas, and if amplification is going to occur, it is generally present at the time of diagnosis.

Abnormal calcium metabolism caused by increased circulating 1,25-dihydroxyvitamin D in a patient with rheumatoid arthritis

A 35-year-old white male with rheumatoid arthritis who had developed hypercalcemia, hypercalciuria, and nephrolithiasis was found to be abnormally sensitive to vitamin D as a result of lack of regulation of circulating 1,25-dihydroxyvitamin D (1,25-(OH)2D). An increase in daily intake of vitamin D from 10 micrograms (400 units) per day to 50 micrograms (2000 units) per day produced an abnormal elevation in serum 1,25-(OH)2D, hypercalcemia, and hypercalciuria which were corrected by prednisone. Serum 25-hydroxyvitamin D initially was abnormally low, and increased with vitamin D to values which were in the low normal range. There were significant positive correlations between serum 1,25-(OH)2D (p less than .05) and serum calcium and between serum 1,25-(OH)2D and urinary calcium (p less than .05). Serum immunoreactive parathyroid hormone, initially in the lower range of normal, decreased further during hypercalcemia. A radiograph of the chest, gallium scan, and serum angiotensin-converting enzyme activity were normal. No granulomas or evidence of lymphoma were found in biopsies of the liver and of several lymph nodes. It is concluded that the abnormal calcium metabolism in this patient resulted from increased circulating 1,25-(OH)2D and that the defect in vitamin D metabolism was not related to sarcoidosis, other granulomatous disease, Hodgkin's disease, or lymphoma. The relationship, if any, of the abnormal metabolism of vitamin D and calcium to rheumatoid arthritis remains to be established.

Radiochromium distribution in aged rats

Fragmentary studies suggest that tissue chromium (Cr) levels decrease with age. Regardless of the mechanism for such a decline, decreased tissue exchange with administered radiochromium (51Cr) should result. Accordingly, body retention, urinary excretion, and serum (plasma) and tissue levels of 51Cr were determined in 2-month-old male control rats and in 9-18-month-old experimental male rats 3 days after the intravenous injection of high specific activity trivalent 51Cr. The older rats retained relatively less 51Cr than the 2-month-old rats in comparison to body weight but had similar urinary excretions of 51Cr. Serum (plasma) 51Cr levels were generally higher and tissue 51Cr levels generally lower in the older rats, with the exception of spleen 51Cr content, which increased. Skeletal 51Cr content was markedly decreased, by 30-85%. These data suggest that aging alters 51Cr distribution by decreasing cellular Cr content and transport. Other mechanisms must be operative in bone since skeletal Cr is primarily extracellular.

Radiochromium distribution during saline diuresis

Free water diuresis in vasopressin-deficient Brattleboro rats does not influence body conservation of chromium (Cr+3), suggesting a proximal tubular site for renal Cr reabsorption. Other data suggest that Cr conservation is accomplished primarily by lack of glomerular filtration or by tissue binding to a specific Cr-binding substance. To provide further data, radiochromium (51Cr) retention and tissue distribution were studied in SHR and WKY rats undergoing saline diuresis. Despite high urine flows, body retention and urinary excretion of 51Cr were unchanged. Tissue content of 51Cr was minimally and not consistently influenced by saline diuresis in either rat strain. Compared to WKY rats, the SHR rats had a trend to lower serum and tissue 51Cr content but higher tissue/serum 51Cr ratios. These data fail to incriminate collecting duct reabsorption in Cr conservation but are compatible with proximal Cr reabsorption or either of the two hypotheses mentioned above. The decreased serum 51Cr content of SHR rats may be due to the mechanical effect of increased plasma and extracellular volumes. One possible explanation for the increased tissue/serum 51Cr ratios may be the presence of a factor in SHR rats promoting cellular Cr transport. However, there is no present evidence to suggest that any of the hormones believed capable of increasing Cr transport (insulin, growth hormone, thyroxine, ADH) are increased in the SHR rat.

Clinical and biochemical aspects of chromium deficiency

The essentiality of chromium (Cr) in animal and human nutrition is now well accepted. In animals, Cr deficiency can cause a diabetic-like state, impaired growth, elevated blood lipids, increased aortic plaque formation, and decreased fertility and longevity. The ability of Cr to potentiate insulin sensitivity has considerable experimental support. In the human, Cr deficiency has been demonstrated unequivocally in only one clinical situation, patients on total parenteral nutrition without added Cr. In such patients, impaired glucose tolerance, hyperglycemia, relative insulin resistance, peripheral neuropathy, and a metabolic encephalopathy have been noted with reversal of the clinical phenomena by Cr repletion. Many studies have been performed to determine whether Cr deficiency may be important in other clinical conditions, namely, diabetes mellitus, pregnant and parous women, and the aged population. Available data indicate that Cr supplementation can improve glucose metabolism in glucose intolerant individuals and decrease the total/HDL cholesterol ratio regardless of the status of glucose tolerance. However, whether Cr supplementation has long-term health benefits is unknown. Further, despite many tantalizing observations, it is still unclear whether Cr deficiency, latent or overt, is common in any human situation other than generalized malnutrition and total parenteral nutrition without added Cr. Technical uncertainties in the analysis of Cr, Cr contamination of food by the use of stainless steel processing equipment and eating utensils, and the lack of a clinically feasible test for Cr deficiency continue to impede progress in Cr research. Nevertheless, there is considerably more clarity as to plasma and urine Cr levels, food and tissue Cr content, and metabolic pathways of Cr metabolism than existed a decade ago. It is expected that progress will accelerate, since critical questions can now be addressed regarding the role of Cr in human nutrition.

Optic neuropathy in Paget's disease

Of 22 patients (18 men and four women ranging in age from 50 to 89 years) with radiographic and clinical evidence of Paget's disease, nine had visual field defects. All nine had arcuate scotomas and five of the nine had generalized constriction. The visual field changes were asymptomatic in six of nine patients and progressive in two patients. Only two patients had radiographic evidence of optic canal constriction by bony impingement. There was no objective improvement in the optic neuropathy in the three patients treated with synthetic salmon calcitonin. Our data suggested that the optic neuropathy of Paget's disease cannot be explained solely on the basis of bony compression and the cause of optic neuropathy in patients with normal optic canals remains unknown.

Placental transport of chromium

Since trivalent chromium (Cr+3) transport into certain tissues is rapid, the placental transport of injected high specific activity 51Cr+3 was studied in pregnant rats at days 17-20 of gestation. Three days after the intravenous injection of 51Cr+3, body retention of 51Cr was similar in pregnant and nonpregnant rats, but in the pregnant rats placentofetal uptake of 51Cr accounted for 25-30% of the 51Cr retention. The mean 51Cr content per placentofetal unit was 0.89 +/- 0.03% injected dose. Serum and tissue 51Cr contents per milliliter or gram in the pregnant rats were decreased by 50-80% except in uterus, which was unchanged. Tissue/serum 51Cr ratios were increased by 70-300% in the pregnant rats compared to the nonpregnant controls. These results indicate that the placentofetal unit is capable of extracting large amounts of Cr from the mother, and support the suggestion that maternal Cr is depleted during pregnancy. The data also suggest that body tissues may defend their Cr stores against Cr depletion by adaptive cellular Cr transport mechanisms.

Pancreatic exocrine function and cyclic nucleotides in the diabetic rat

Streptozotocin-induced diabetes mellitus in the rat results in a 30% decrease in serum amylase and an 80% decrease in pancreatic amylase levels. Pancreatic trypsinogen levels decrease 50% whereas pancreatic lipase levels increase 30%. Plasma cyclic nucleotide levels (cAMP and cGMP) increase 40-100%, urine cyclic nucleotide levels decrease 75-99%, but pancreatic cyclic nucleotide levels are unchanged. Short-term insulin treatment restores pancreatic amylase and trypsinogen levels to normal but has no effect on serum amylase or pancreatic lipase levels. Plasma cAMP levels decrease 20% toward normal during insulin treatment, but no other effects on cyclic nucleotide levels occur. These data confirm the profound but reversible effect of experimental diabetes mellitus on pancreatic secretion of amylase and trypsinogen. The results suggest that cyclic nucleotides do not play a direct role in the generation of pancreatic exocrine deficiency in diabetes mellitus or its reversal by insulin.

Effects of furosemide on biliary secretion, pancreatic blood flow, and pancreatic exocrine secretion

The effects of furosemide on biliary secretion and on pancreatic hemodynamics and exocrine function were studied by quantitative flowmetry and timed collections of biliary and pancreatic exocrine secretion in the anesthetized dog. Biliary flow and the output of its components (Na+, K+, Ca, Mg, 3-OH bile salts, and bilirubin) increased significantly following a furosemide injection of 0.6 mg/kg and rose progressively to 75-150 per cent above basal levels as the furosemide dose was increased to 9.6 mg/kg. Pretreatment with secretin had no influence on furosemide-induced biliary secretion. Furosemide doses of 4.8 and 9.6 mg/kg increased blood flow in the superior pancreaticoduodenal arterial bed by 30-60 per cent but did not alter flow in the inferior pancreaticoduodenal arterial bed or the pancreatic branch of the splenic artery. However, small increases were seen in flow in the latter two arterial beds after furosemide when secretin administration preceded furosemide. Basal pancreatic secretion was not affected by furosemide, but pretreatment with a submaximal sustaining infusion of secretin uncovered a furosemide action to increase pancreatic exocrine flow and the outputs of Na+, K+, Ca, Mg, and enzymes by 25-35 per cent. These data extend previous studies of the gastrointestinal vasodilator effects of furosemide to the pancreatic circulation and previous data demonstrating furosemide-induced ionic transport in nonrenal systems to biliary, pancreatic acinar, and ductular transport in both organs. Whether the augmentation of pancreatic blood flow is secondary to enhanced ion transport in the exocrine pancreas or to an effect on ionic cotransport in vascular smooth muscle is unknown.