A short-term study of the safety, pharmacokinetics, and efficacy of ritonavir, an inhibitor of HIV-1 protease. European-Australian Collaborative Ritonavir Study Group

BACKGROUND

Reverse-transcriptase inhibitors have only moderate clinical efficacy against the human immunodeficiency virus type 1 (HIV-1). Ritonavir is an inhibitor of HIV-1 protease with potent in vitro anti-HIV properties and good oral bioavailability.

METHODS

We evaluated the antiviral activity and safety of ritonavir in a double-blind, randomized, placebo-controlled phase 1 and 2 study of 84 HIV-positive patients with 50 or more CD4+ lymphocytes per cubic millimeter. The patients were randomly assigned to one of four regimens of ritonavir therapy, or to placebo for four weeks and then (by random assignment) to one of the ritonavir regimens.

RESULTS

During the first 4 weeks, increases in CD4+ lymphocyte counts and reductions in the log number of copies of HIV-1 RNA per milliliter of plasma were similar among the four dosage groups, but in the three lower-dosage groups there was a return to base-line levels by 16 weeks. After 32 weeks, in the seven patients in the highest-dosage group (600 mg of ritonavir every 12 hours), the median increase from base line in the CD4+ lymphocyte count was 230 cells per cubic millimeter, and the mean decrease in the plasma concentration of HIV-1 RNA (as measured by a branched-DNA assay) was 0.81 log (95 percent confidence interval, 0.40 to 1.22). In a subgroup of 17 patients in the two higher-dosage groups, RNA was also measured with an assay based on the polymerase chain reaction, and after eight weeks of treatment there was a mean maximal decrease in viral RNA of 1.94 log (95 percent confidence interval, 1.37 to 2.51). Adverse events included nausea, circumoral paresthesia, elevated hepatic aminotransferase levels, and elevated triglyceride levels. Ten withdrawals from the study were judged to be related to ritonavir treatment.

CONCLUSIONS

In this short-term study, ritonavir was well tolerated and had potent activity against HIV-1, but its clinical benefits remain to be established.

Smoked medicinal cannabis for neuropathic pain in HIV: a randomized, crossover clinical trial

Despite management with opioids and other pain modifying therapies, neuropathic pain continues to reduce the quality of life and daily functioning in HIV-infected individuals. Cannabinoid receptors in the central and peripheral nervous systems have been shown to modulate pain perception. We conducted a clinical trial to assess the impact of smoked cannabis on neuropathic pain in HIV. This was a phase II, double-blind, placebo-controlled, crossover trial of analgesia with smoked cannabis in HIV-associated distal sensory predominant polyneuropathy (DSPN). Eligible subjects had neuropathic pain refractory to at least two previous analgesic classes; they continued on their prestudy analgesic regimens throughout the trial. Regulatory considerations dictated that subjects smoke under direct observation in a hospital setting. Treatments were placebo and active cannabis ranging in potency between 1 and 8% Delta-9-tetrahydrocannabinol, four times daily for 5 consecutive days during each of 2 treatment weeks, separated by a 2-week washout. The primary outcome was change in pain intensity as measured by the Descriptor Differential Scale (DDS) from a pretreatment baseline to the end of each treatment week. Secondary measures included assessments of mood and daily functioning. Of 127 volunteers screened, 34 eligible subjects enrolled and 28 completed both cannabis and placebo treatments. Among the completers, pain relief was greater with cannabis than placebo (median difference in DDS pain intensity change, 3.3 points, effect size=0.60; p=0.016). The proportions of subjects achieving at least 30% pain relief with cannabis versus placebo were 0.46 (95%CI 0.28, 0.65) and 0.18 (0.03, 0.32). Mood and daily functioning improved to a similar extent during both treatment periods. Although most side effects were mild and self-limited, two subjects experienced treatment-limiting toxicities. Smoked cannabis was generally well tolerated and effective when added to concomitant analgesic therapy in patients with medically refractory pain due to HIV DSPN.

Adjunctive intranasal oxytocin reduces symptoms in schizophrenia patients

BACKGROUND

Both human and animal studies suggest oxytocin may have antipsychotic properties. Therefore, we conducted a clinical trial to directly test this notion.

METHODS

Nineteen schizophrenia patients with residual symptoms despite being on a stable dose of at least one antipsychotic were enrolled in a randomized, double-blind, crossover study. They received 3 weeks of daily intranasal oxytocin (titrated to 40 IU twice a day) and placebo adjunctive to their antipsychotics. Order of intranasal treatment was randomly assigned and there was a 1-week washout between treatments.

RESULTS

Analysis of the 15 subjects who completed all the study visits revealed that oxytocin significantly reduced scores on the Positive and Negative Symptom Scale (p < .001) and Clinical Global Impression-Improvement Scale (p < .001) compared with placebo at the 3-week end point. No benefit was seen at the early time points. Oxytocin was well tolerated and produced no adverse effects based upon patient reports or laboratory analysis.

CONCLUSIONS

The results support the hypothesis that oxytocin has antipsychotic properties and is well tolerated. Higher doses and longer duration of treatment may produce larger benefits and should be evaluated in future studies.

A multicenter randomized controlled trial of a plant-based nutrition program to reduce body weight and cardiovascular risk in the corporate setting: the GEICO study

Background/objectives:

To determine the effects of a low-fat plant-based diet program on anthropometric and biochemical measures in a multicenter corporate setting.

Subjects/methods:

Employees from 10 sites of a major US company with body mass index ⩾25 kg/m² and/or previous diagnosis of type 2 diabetes were randomized to either follow a low-fat vegan diet, with weekly group support and work cafeteria options available, or make no diet changes for 18 weeks. Dietary intake, body weight, plasma lipid concentrations, blood pressure and glycated hemoglobin (HbA_1C) were determined at baseline and 18 weeks.

Results:

Mean body weight fell 2.9 kg and 0.06 kg in the intervention and control groups, respectively (P<0.001). Total and low-density lipoprotein (LDL) cholesterol fell 8.0 and 8.1 mg/dl in the intervention group and 0.01 and 0.9 mg/dl in the control group (P<0.01). HbA_1C fell 0.6 percentage point and 0.08 percentage point in the intervention and control group, respectively (P<0.01).

Among study completers, mean changes in body weight were −4.3 kg and −0.08 kg in the intervention and control groups, respectively (P<0.001). Total and LDL cholesterol fell 13.7 and 13.0 mg/dl in the intervention group and 1.3 and 1.7 mg/dl in the control group (P<0.001). HbA_1C levels decreased 0.7 percentage point and 0.1 percentage point in the intervention and control group, respectively (P<0.01).

Conclusions:

An 18-week dietary intervention using a low-fat plant-based diet in a corporate setting improves body weight, plasma lipids, and, in individuals with diabetes, glycemic control.

Increasing access to child mental health services for urban children and their caregivers

This article presents the results of a study that evaluated the effects of two engagement interventions on the initial attendance and ongoing retention in child mental health services of 109 primarily children of color and their families. Both the combined intervention (telephone and first interview) and the telephone-alone intervention were associated with significant increases in attendance at initial intake appointments over the usual intake procedure, but only the combined intervention was related to the greater ongoing use of services. Implications for future research and recommendations for modifying procedures in outpatient child mental health centers are also presented.

Clinical, serologic, and immunogenetic studies in childhood-onset systemic lupus erythematosus

OBJECTIVE

To determine the frequency of systemic lupus erythematosus (SLE)-associated clinical manifestations, autoantibodies, and HLA class II alleles in a large cohort of patients with childhood-onset SLE.

METHODS

Eighty children with SLE onset before age 18 (27 before age 11) were studied for the frequency of renal, neuropsychiatric, and hematologic complications as well as for anti-native DNA, Ro, La, Sm, and U1 RNP autoantibodies. HLA-DR, DQ, and DP alleles were determined by oligotyping. The results were compared with findings in 213 adults with SLE onset at or after age 18 years.

RESULTS

Renal involvement was more frequent in those with childhood-onset SLE, especially those with onset before age 11 (82%, compared with 53% in adults). Anti-U1 RNP was more common in American blacks with SLE onset before age 18. HLA-DRB1*0301, DQA1*0501, DQB1*0201 was more common in Caucasians and DRB1*1503, DRB5*0101, DQA1*0102, DQB1*0602 in American blacks, regardless of age at SLE onset. Anti-Sm autoantibodies were most highly associated with HLA-DQA1*0102 and DQB1*0602.

CONCLUSION

While childhood-onset SLE shares many immunogenetic and serologic similarities to adult-onset disease, important clinical differences nevertheless exist in children with this disease.

Human papillomavirus infection in sexually active adolescent females: prevalence and risk factors

We examined the prevalence of human papillomavirus (HPV) infection, and associated risk factors for infection with HPV types 6, 11, 16, 18, 31, 33, and 35, in 661 sexually active adolescent females attending family planning clinics. Fifteen percent were positive for HPV DNA by RNA-DNA dot-blot hybridization. More than 60% of the HPV-positive subjects harbored at least one of the following cancer-related HPV types: 16, 18, 31, 33, or 35. Those with HPV had a mean range of four to 10 lifetime sexual partners compared with a mean range of one to three in those without HPV (p less than 0.001). After the analysis was adjusted for number of lifetime sexual partners, no other risk factor was associated with HPV infection. We conclude that oncogenic-related HPV types are common sexually transmitted organisms found in our population. The strong relationship with number of sexual partners suggests that acquisition of HPV infection is predominantly influenced by sexual behavior. However, in our population, confounders such as oral contraceptive use, past history of Chlamydia trachomatis infection, or substance abuse were not found to be significant independent risk factors.

A review of randomized trials of psychiatric consultation-liaison studies in primary care

The field of consultation-liaison (C-L) psychiatry has developed a variety of research interventions to try to improve the recognition and treatment of mental disorders in primary care. The authors review the results of three generations of randomized trials of mental health interventions developed by C-L psychiatrists. In general, these trials have been more successful in improving detection of mental illness and increasing the application of mental health treatments by primary care physicians than in changing patient outcomes. The results of these randomized trials are interpreted by using models developed in the health services field.

Temperature dependence of dipalmitoyl phosphatidylcholine monolayer stability

Dipalmitoyl phosphatidylcholine is the principal component of lung surfactant, and knowledge of its behavior as a film spread at the air-water interface is essential for understanding how lung surfactant itself works. We therefore studied the collapse rates of very low surface tension air-water monolayers of dipalmitoyl, dimyristoyl, and palmitoyl-myristoyl phosphatidylcholines at different temperatures. In each case we found that the monolayers abruptly became unstable at temperature 3-4 degree C above their bulk lipid-water phase transition temperatures (Tc). This accords with a comparable increase in Tc occurring in bulk systems subjected to high pressure. These findings are also consistent with the behavior of isolated rat lungs, which have been found to require higher transmural pressures to maintain a given volume on deflation when kept at temperature above the Tc of dipalmitoyl phosphatidylcholine.

Immune status as a determinant of human papillomavirus detection and its association with anal epithelial abnormalities

One hundred and twenty Danish homosexual men were enrolled to characterize risk factors for anal type-specific human papillomavirus (HPV) expression and to examine its association with anal epithelial atypia. Detection of HPV strongly correlated with immunosuppression measured by T-lymphocyte subset markers and rose nearly linearly from 7.3% among subjects with CD4/CD8 ratios above 1.0 to 35.3% among those with a ratio below 0.4 (p trend = 0.003). No association was found between presence of HPV and a wide range of lifestyle factors including number of sex partners/year, smoking, alcohol consumption and illegal drug intake. However, self-reported history of anal condyloma in the past year was correlated with HPV (p less than 0.001). Simultaneous testing for presence of HPV in the oral cavity showed evidence of HPV 16,18 and 31,33,35. Anal smears were abnormal in 19.5% of the men and correlated strongly with presence of HPV (OR = 6.1, p less than 0.001). Type-specific associations were found with HPV 31/33/35 (OR = 8.5) and HPV 16/18 (OR = 3.1) only. The association remained significant after adjusting for immune status. Overall, HPV was detected in 50% of the cases with abnormal smears. However, HPV was found in all subjects with abnormal smears and a CD4/CD8 ratio below 0.4, compared to only 3 of 14 subjects with abnormal smears and a ratio greater than or equal to 1.3. In conclusion, (1) HPV may be missed in a substantial number of infected subjects with a normal immune system. This may have an impact on studies trying to describe risk factors for HPV transmission and its correlation with cancer development. (2) The finding of HPV 16,18 and 31,33,35 in the oral cavity makes oral-genital sexual activity at least a hypothetical route of transmission for these HPV types. (3) HPV appears to play a central role in the development of anal epithelial abnormality.

Interaction of human immunodeficiency and papilloma viruses: association with anal epithelial abnormality in homosexual men

During the 7th annual follow-up of our cohort of homosexual men in 1989, we tested the hypotheses that infection with human immunodeficiency virus (HIV) may enhance the expression of human papilloma virus (HPV) and that the development of anal epithelial abnormality is related to a biologic interaction between these two viruses. Overall, 41 (39%) of the 105 men had anal swabs positive for one or more genotypes of HPV 6/11, 16/18 or 31/33/35. Twenty-three (53%) of the 43 HIV-positive subjects harbored HPV compared to 18 (29%) of the 64 HIV-negative subjects (p = 0.012), including higher prevalence rates for HPV genotypes 16/18 (p = 0.01), 6/11 (p = 0.007), and 31/33/35 (p = 0.07). Multivariate logistic regression analysis of the HIV-positive subjects showed low CD4+ cell counts to be an independent risk factor for detection of HPV (p = 0.04) and in particular for HPV genotypes 31/33/35 (p = 0.02) and 6/11 (p = 0.07). In contrast, similar analysis of the HIV-negative subset showed that a positive antibody test for syphilis was associated with HPV (p = 0.03). Anal epithelial abnormalities were found in 13 (14%) of 92 technically adequate cytologic smears and were strongly associated with detection of any HPV genotypes by the dot-blot method (p = 0.01), and in particular with HPV genotypes 6/11 (p = 0.001). None of 15 subjects with HPV detected only by PCR had anal epithelial abnormality. We propose a viral interaction model, in which HIV-related immune deficiency allows reactivation of HPV, with a subsequent or concomitant appearance of epithelial abnormality.

Measurement of mechanical properties of bone material in vitro by ultrasound reflection: methodology and comparison with ultrasound transmission

An ultrasound reflection technique was designed and implemented to study the mechanical properties of bone material. The technique uses the fact that an ultrasound beam produced in water undergoes total internal reflection off a bone sample at a critical angle formally related to the velocity of a pressure wave in bone. When the plane of scattering is rotated around the normal to the sample surface, the critical angle varies with a periodic dependence dictated by the intrinsic symmetry of the bone structure at the point being examined. Most current measurements of sound velocity are made using transmission techniques. A double-blind intercomparison between this technique and a transmission technique, which was previously validated against tensile mechanical testing, was performed for samples of isotropic materials and of human cortical bone. Strong correlations were found for both sets of samples. For the isotropic materials the velocities were approximately equal, but for bone they were on average 11% higher in reflection than in transmission. This was the result both of the higher frequency employed in reflection (3.5 rather than 2.25 MHz) and of the different effects of sample imperfections on the two measurements. In particular, the reflection technique used in this work studied the surface of the sample, but the ultrasound beam in the transmission method propagated through its interior. In assessing the mechanical properties of bone specimens by ultrasound, the reflection technique samples a discrete bone surface element and the transmission method analyzes the entire volume of the specimen. Thus the reflection technique may yield a measure of the mechanical property of bone trabeculae that is largely unaffected by the mass of the entire specimen, but mass and the structural density of the specimen affect the transmission method.

Long-term treatment of obsessive-compulsive disorder after an acute response: a comparison of fluoxetine versus placebo

Few controlled studies have evaluated the long-term continuation of pharmacotherapy for relapse prevention in patients with obsessive-compulsive disorder (OCD). This study assessed efficacy and safety of fluoxetine versus placebo in preventing relapse of OCD during a 52-week period in responders to short-term administration of fluoxetine. Patients who met DSM-IV criteria for OCD and had a Yale-Brown Obsessive Compulsive Scale score > or = 19 were treated with single-blind fluoxetine 20, 40, or 60 mg/day (based on physician assessment of response and tolerability). After 20 weeks, responders were randomly assigned to receive continued treatment with fluoxetine or placebo and were monitored for relapse for up to 52 weeks. Of 130 patients who entered the study, 71 (55%) were randomly assigned to receive fluoxetine (N = 36) or placebo (N = 35). Patients who received fluoxetine had numerically lower relapse rates compared with those who received placebo, although the difference was not significant (Kaplan-Meier 1-year relapse rates: fluoxetine, 20.6%; placebo, 31.9%; one-tailed p value = 0.137). In additional analyses evaluating patients on the basis of fluoxetine dose at randomization, patients who continued treatment with fluoxetine 60 mg/day (N = 52) had significantly lower rates of relapse than those who were switched to placebo (Kaplan-Meier 1-year relapse rates: fluoxetine, 17.5%; placebo, 38.0%; one-tailed p value = 0.041). Those who responded to the acute treatment phase with 40 (N = 18) or 20 (N = 1) mg/day had low overall rates of relapse, and the difference between continued fluoxetine and placebo treatment for these patients was not significant. For responders to the 60 mg/day dosage, those patients who continued treatment with fluoxetine were provided greater protection against relapse than those patients switched to placebo.

A dietary intervention for chronic diabetic neuropathy pain: a randomized controlled pilot study

Background:

Diabetic neuropathy is a common and often debilitating condition for which available treatments are limited. Because a low-fat plant-based diet has been shown to improve glycemic control in individuals with type 2 diabetes, we hypothesized that such a diet would reduce painful symptoms of diabetic neuropathy.

Methods:

In this 20-week pilot study, individuals with type 2 diabetes and painful diabetic neuropathy were randomly assigned to two groups. The intervention group was asked to follow a low-fat, plant-based diet, with weekly classes for support in following the prescribed diet, and to take a vitamin B12 supplement. The control group was asked to take the same vitamin B12 supplement, but received no other intervention. At baseline, midpoint and 20 weeks, clinical, laboratory and questionnaire data were collected. Questionnaires included an analog ‘worst pain' scale, Michigan Neuropathy Screening Instrument, global impression scale, Short Form McGill Pain Questionnaire, Neuropathy Total Symptom Score, a weekly pain diary and Norfolk Quality of Life Questionnaire.

Results:

After 20 weeks, body weight change with the intervention was −6.4 kg (95% confidence interval (CI) −9.4 to −3.4, P<0.001) in an effect size analysis. Electrochemical skin conductance in the foot improved by an average of 12.4 microseimens (95% CI 1.2–23.6, P=0.03) with the intervention in an effect size analysis. The between-group difference in change in pain, as measured by the McGill pain questionnaire, was −8.2 points (95% CI −16.1 to −0.3, P=0.04). Michigan Neuropathy Screening Instrument questionnaire score change was −1.6 points (95% CI −3.0 to −0.2, P=0.03).

Conclusions:

Improvements were seen in some clinical and pain measures. This pilot study suggests the potential value of a plant-based diet intervention, including weekly support classes, for treating painful diabetic neuropathy.

Transcriptional regulation of human pulmonary surfactant proteins SP-B and SP-C by glucocorticoids

Expression of the pulmonary surfactant-associated proteins SP-B and SP-C is under both developmental and hormonal regulation. We used human fetal lung to investigate developmental changes and the mechanism of glucocorticoid stimulation of SP-B and SP-C gene expression. There were similar approximately 3-fold increases in SP-B cytoplasmic mRNA content and transcription rate comparing lung samples of 24 wk versus 16 wk gestation. During 5 days of lung explant culture without hormones, the transcription rate increased for SP-B and decreased for SP-C, paralleling changes in mRNA content. Treatment with 100 nM dexamethasone maximally increased transcription of the SP-B gene (approximately 3-fold) and SP-C gene (approximately 11-fold) after 2 and 8 h, respectively, similar to changes in mRNA content. In dose-response studies, the maximal increase in transcription rate occurred at approximately 10 nM dexamethasone for SP-B and at > or = 100 nM for SP-C. Induction of SP-B mRNA content and transcription rate were not affected by prior cycloheximide exposure, whereas induction of SP-C mRNA was decreased by as little as 1 h exposure to inhibitor. We conclude that glucocorticoids, acting directly in type II cells, regulate the SP-B and SP-C genes primarily at the level of transcription. Induction of SP-C, but not SP-B, requires ongoing protein synthesis which likely reflects involvement of a labile transcription factor. The difference in glucocorticoid sensitivity may indicate that the two surfactant protein genes contain glucocorticoid response elements with different affinities for receptor.

Prevalence of astroviruses in a children's hospital

An enzyme immunoassay for astrovirus was used to screen 357 stool samples from 267 symptomatic inpatients at a tertiary-care children's hospital. Thirty stool samples from 26 patients contained astrovirus antigen, while rotavirus was found in 34 samples and Clostridium difficile toxin was found in 40. Half of the astrovirus infections were nosocomial. Additional pathogens were identified in six of the astrovirus antigen-positive stool samples. Most (80%) of the astroviruses recovered were of serotype 1. Astrovirus infections were significantly more common than rotavirus or C. difficile infections in very young infants and in those with surgical short-bowel syndrome.

Measurement of intrinsic bone quality in vivo by reflection ultrasound: correction of impaired quality with slow-release sodium fluoride and calcium citrate

The intrinsic (material) quality of cancellous and cortical bone was evaluated in vivo from the measurement of reflection ultrasound velocities in the ulna. In cancellous bone, the reflection ultrasound velocity was inversely correlated with age in normal women (r = -0.48, p = 0.001), with a significantly lower mean value in 32 normal postmenopausal women than in 14 premenopausal women (3124 versus 3341 m/s, p < 0.0001). In 32 untreated osteoporotic women the cancellous bone velocity was lower than in normal postmenopausal subjects (2906 versus 3124 m/s, p = 0.0001). Following treatment with slow-release sodium fluoride plus calcium citrate (mean 2.4 years in 33 osteoporotic patients with no fracture during treatment), the cancellous bone velocity was significantly higher than in untreated osteoporotic women (3082 versus 2906 m/s, p = 0.0002) and was not significantly different from that in normal postmenopausal women. The cortical bone velocity displayed similar trends, but the changes did not attain statistical significance. The measurements were repeated approximately 9 months later in 9 untreated and in 20 treated patients; in 5 additional patients, the measurements were made both before and after 9 months of treatment with slow-release sodium fluoride and calcium citrate. The cancellous bone velocity increased significantly (p = 0.046) in these patients, from 3008 m/s before treatment to 3112 m/s after the first 9 months of treatment. The velocity rose significantly from 3037 to 3167 m/s (p = 0.017) in patients treated for a short time (12-30 months at first measurement), but it did not change in untreated patients or those treated for more than 30 months. Thus, the material quality of cancellous bone decreases with normal aging and is reduced further with the osteoporotic process. This impaired quality may be corrected by treatment with slow-release sodium fluoride plus calcium citrate.

Cost-effectiveness of newer antidepressants compared with tricyclic antidepressants in managed care settings

BACKGROUND

Our aim was to determine the cost-effectiveness of newer antidepressants compared with tricyclic antidepressants in managed care organization settings.

METHOD

We employed cost-utility analysis based on a clinical decision analysis model derived from published medical literature and physician judgment. The model, which represents ideal primary care practice, compares treatment with nefazodone to treatment with either imipramine or fluoxetine or to a step approach involving initial treatment with imipramine followed by nefazodone for treatment failures. The outcome measures were lifetime medical costs, quality-adjusted life years (QALYs), and costs per QALY gained.

RESULTS

The base case analysis found that nefazodone treatment had $16,669 in medical costs, compared with $15,348 for imipramine, $16,061 for the imipramine step approach, and $16,998 for fluoxetine. QALYs were greatest for nefazodone (14.64), compared with 14.32 for imipramine, 14.40 for the step approach, and 14.58 for fluoxetine. The cost-effectiveness ratio comparing nefazodone with imipramine was $4065 per QALY gained. The cost-effectiveness ratio comparing nefazodone with the step approach was $2555 per QALY gained. There were only minor differences in costs and outcomes between nefazodone and fluoxetine, with nefazodone resulting in $329 fewer costs and 0.06 more QALYs. The cost-effectiveness ratios comparing fluoxetine with imipramine and with the step approach were $6346 per QALY gained and $5206 per QALY gained, respectively. In the sensitivity analyses, the cost-effectiveness ratios comparing nefazodone and imipramine ranged from $2572 to $5841 per QALY gained. The model was most sensitive to assumptions about treatment compliance rates.

CONCLUSION

The findings suggest that nefazodone is a cost- effective treatment compared with imipramine or fluoxetine treatment for major depression. Fluoxetine is cost-effective compared with imipramine treatment, but is estimated to have slightly more medical costs and less effectiveness compared with nefazodone. The basic findings and conclusions do not change even after modifying key model parameters.

Anaphylactic shock in pregnancy: a case study and review of the literature

We describe a 22-year-old previously healthy primigravida who presented with spontaneous rupture of membranes at 40 weeks of gestation. Because of her history of inadequate prenatal care, a chemoprophylaxis regimen against group B streptococcal infection was prescribed upon admission. Within a few minutes after initiation of an i.v. infusion of penicillin G, the patient developed generalized erythema and severe hypotension, which was essentially unresponsive to intravenous boluses of ephedrine. Following stabilization of maternal blood pressure with incremental doses of epinephrine, emergency cesarean section was performed with delivery of a severely depressed neonate. Postoperative recovery of the mother was uneventful, although the baby was diagnosed to have suffered significant neurological damage. This unfortunate event highlights the therapeutic dilemma in anaphylaxis during pregnancy, a relatively rare but potentially life-threatening event. A critical review of the scientific literature reveals several etiological agents for anaphylaxis during the perioperative period, with penicillin as the leading cause of anaphylaxis-related mortality. Although epinephrine is the vasopressor of choice during hemodynamic resuscitation in the non-pregnant patient, during pregnancy it may pose a risk to the placental-fetal circulation. Additionally, upon review of the various published reports to date, timing and mode of delivery of the neonate in the face of anaphylactic shock remains controversial.

Glucocorticoid stimulation of fatty acid synthesis in explants of human fetal lung

We examined the effects of glucocorticoids and thyroid hormone (T3) on fatty acid synthesis, fatty acid composition and fatty acid synthetase activity in explants of human fetal lung (16-23 wk gestation). Explants were cultured 1-7 days in the absence (control) or presence of dexamethasone (10 nM) and/or T3 (2 nM). In control explants fatty acid synthesis and fatty acid synthetase activity increased 200% and 455%, respectively, between 1 and 5 days. Dexamethasone (10 nM) stimulated fatty acid synthesis (tritiated water incorporation) 155% and fatty acid synthetase activity 117% after 5 days in culture. T3 (2 nM) was not stimulatory, either alone or in the presence of dexamethasone. Dexamethasone increased the proportion of newly synthesized fatty acid recovered in phosphatidylcholine from 72% (control) to 90% (P less than 0.02) of total fatty acid. Dexamethasone stimulation of fatty acid synthetase activity was consistent with a receptor-mediated process: (1) stimulation was saturable and dose-dependent (Kd = 1.5 +/- 0.3 nM); (2) the potency of glucocorticoid analogs and other steroids reflected their glucocorticoid activity; (3) stimulation was reversible when cortisol was removed from the medium. Stimulation by dexamethasone was apparent within 24 h of hormone exposure, and increased to a maximum between 4 and 6 days. Fatty acid synthetase activity was higher in Type II cells (3.54 +/- 0.58 nmol malate/min per mg protein) than in fibroblasts from treated explants. Although both cell types responded to hormone treatment the stimulation was greater for Type II cells (200% vs. 75% increase). The fatty acid composition of PC showed increases in 14:0 and 16:1 with culture alone which were further stimulated by dexamethasone but not T3. These results indicate glucocorticoid stimulation of fatty acid synthesis and are consistent with a key role for fatty acid synthetase in the hormonal induction of pulmonary surfactant phosphatidylcholine synthesis in cultured fetal lung.

Lamellar bodies of cultured human fetal lung: content of surfactant protein A (SP-A), surface film formation and structural transformation in vitro

Lamellar bodies were isolated from dexamethasone and T3-treated explant cultures of human fetal lung, using sucrose density-gradient centrifugation. We examined their content of surfactant apoprotein A (SP-A), and their ability to form surface films and to undergo structural transformation in vitro. SP-A measured by ELISA composed less than 2% of total protein within lamellar bodies; this represented, as a minimum estimate, a 2-12-fold enrichment over homogenate. One- and two-dimensional gel electrophoresis also suggested that SP-A was a minor protein component of lamellar bodies. Adsorption of lamellar bodies to an air/water interface was moderately rapid, but accelerated dramatically upon addition of exogenous SP-A in ratios of 1:2-16 (SP-A:phospholipid, w/w). Similar adsorption patterns were seen for lamellar bodies from fresh adult rat and rabbit lung. Lamellar bodies incubated under conditions that promote formation of tubular myelin underwent structural rearrangement only in the presence of exogenous SP-A, with extensive formation of multilamellate whorls of lipid bilayers (but no classical tubular myelin lattices). We conclude that lamellar bodies are enriched in SP-A, but have insufficient content of SP-A for structural transformation to tubular myelin and rapid surface film formation in vitro.

Differential vulnerability of primary cultured cholinergic neurons to nitric oxide excess

Many neuronal nitric oxide synthase (nNOS)-expressing brain neurons, including some cholinergic populations, are resistant to disease or to certain forms of excitotoxicity. Vulnerability to NO excess of forebrain (medial septal/diagonal band; MS-ACh) and brainstem (pedunculopontine/laterodorsal tegmental nuclei; BS-ACh) cholinergic neurons was compared in E16-E18 primary rat brain cultures. MS-ACh cells were approximately 300-fold more sensitive to the NO donor S-nitro-N-acetyl-D,L-penicillamine (SNAP) than were BS-ACh cells. Most (69%) MS-ACh cells contained nuclear DNA fragments by 2 h after addition of SNAP, while only 21% BS-ACh cells were TUNEL-positive after NO excess. Depletion of glutathione content did not potentiate the effect of SNAP on MS-ACh cells, but sensitized BS-ACh cells to the NO donor. Caffeic acid, a putative NF-kappa B inhibitor, enhanced the toxicity of SNAP to cholinergic neurons in both preparations. Our experiments show that cholinergic neurons in mixed primary cultures from different brain regions possess biochemical differences with respect to their vulnerability to NO excess.

The laryngeal mask airway reliably provides rescue ventilation in cases of unanticipated difficult tracheal intubation along with difficult mask ventilation

In 1995, our department of anesthesiology established an airway team to assist in treating unanticipated difficult endotracheal intubations and an airway quality improvement (QI) form to document the use of emergency airway techniques in airway crises (laryngeal mask airway [LMA], flexible fiberoptic bronchoscopy, retrograde intubation [RI], transtracheal jet ventilation [TTJV], and cricothyrotomy). Over a 2-yr period, team members and staff anesthesiologists completed airway QI forms to document the smallest peripheral SpO2 during an airway crisis, the number of direct laryngoscopies (DL) performed before using an emergency airway technique, and the emergency airway technique that succeeded in rescue ventilation. Team members agreed to use the LMA as the first emergency airway technique to treat the difficult ventilation/difficult intubation scenario. A SpO2 value < or =90% during mask ventilation defined difficult ventilation. Inability to perform tracheal intubation by DL defined difficult intubation. An increase in the SpO2 value >90% defined rescue ventilation. Review of airway QI forms from October 1, 1995 until October 1, 1997 revealed 25 cases of difficult ventilation/difficult intubation. Before airway rescue, the median SpO2 was 80% (range 50%-90%), and there were four median attempts at DL (range one to nine). The LMA had a success rate of 94% (95% confidence interval [CI] 77-100). Flexible fiberoptic bronchoscopy, TTJV, RI, and surgical cricothyrotomy had success rates of 50% (95% CI 0-100), 33% (95% CI 0-100), 100% (95% CI 37-100), and 100% (95% CI 37-100), respectively. LMA insertion as the first alternative airway technique was useful in dealing with unanticipated instances of simultaneous difficulty with mask ventilation and tracheal intubation.

IMPLICATIONS

Twenty-five cases of simultaneous difficulty with mask ventilation and tracheal intubation occurred after the induction of general anesthesia during the study period. The laryngeal mask was used in 17 cases, and it provided rescue ventilation without complication in 94% of these cases (95% confidence interval 77-100).

Management of bleeding renal angiomyolipomas by transcatheter embolization following CT diagnosis

Renal angiomyolipomas are commonly associated with spontaneous hemorrhage which can be life-threatening and may require radical nephrectomy for control of hemorrhage. Transcatheter embolization was used in 2 cases of spontaneously bleeding angiomyolipomas; permanent control was achieved in 1 case and temporary control in the other. This more conservative approach was made possible by our ability to diagnose these benign renal tumors confidently using computed tomography.