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Biomedical subjects

K Abrams

Publications and source records attributed to K Abrams.

At least 37 records · Page 2Linked to original sources
PubMed1998

Increased bone resorption in patients with Crohn's disease.

BACKGROUND: Patients with Crohn's disease are at risk of osteoporosis and premature fracture. However, the pathophysiology underlying bone loss remains poorly understood and the optimum treatment has not been established. AIM: To investigate mechanisms of bone loss in Crohn's disease using biochemical markers of bone turnover. METHODS: Bone mineral density was measured at the hip and spine using dual-energy X-ray absorptiometry in 117 patients (48 male) with Crohn's disease. Bone turnover was assessed by measuring serum osteocalcin (BGP), pro-collagen carboxy-terminal propeptide (PICP), bone specific alkaline phosphatase (BALP) and urinary deoxypyridinoline (DPD); and compared to age-matched healthy controls (n = 28). RESULTS: Bone mineral density was reduced (z-score < -1) in 48 (41%) patients with Crohn's disease. Mean values for bone formation markers in patients with Crohn's disease were all within the normal reference range (BGP 8.92 (+/- 3.23) ng/mL (normal range 3.4-10.0), BALP 17.6 (+/- 12.6) U/L (normal range 11.6-43.3), PICP 95.1 (+/- 46.5) ng/mL (normal range 69-163)) and were not significantly different to the control population. However, mean urinary DPD was significantly higher in patients with Crohn's disease compared to healthy controls (10.97 (+/- 9.22) nM DPD/mM creatinine vs. 5.02 (+/- 1.03) nM DPD/mM creatinine, difference in means = 5.95, 95% CI: -9.6 to -2.3, P = 0.00001) and compared to the UK reference range DPD levels were increased in 74 (63%) patients. CONCLUSIONS: Bone resorption as evidenced by urinary DPD was frequently increased in patients with Crohn's disease and was significantly higher than in an age-matched control population. The high levels of urinary DPD suggest increased bone collagen degradation may contribute to osteoporosis in patients with Crohn's disease. These results suggest anti-resorptive agents such as the bisphosphonates may be effective treatment for osteoporosis in Crohn's disease.

Adult↗
PubMed1998

Audit of patients on oral anticoagulants with International normalized ratios of eight or above.

We reviewed retrospectively the medical records of all patients (n = 77, mean age 74.2) on oral anticoagulants with an International normalized ratio (INR) of eight or above in a 12-month period in the Leicestershire District Health Authority (DHA). From a total of 55,625 INRs, 131 (0.24%) were > or = 8. A major cause of over-anticoagulation was unsatisfactory dose loading during in-hospital commencement of oral anticoagulation. The incidence of major bleeding was 12.9% of total episodes of INR > or = 8 with two haemorrhage-related fatalities. Therapy of major haemorrhage with fresh frozen plasma (FFP) and intravenous (i.v) vitamin K proved effective but was not given in a majority of such cases. In conclusion, improvements in initial dose loading of oral anticoagulation and in the management of major haemorrhage are required. Severely over-anticoagulated patients without obvious bleeding should nevertheless receive small dose vitamin K therapy to reduce the risk of haemorrhage related morbidity and mortality without compromising subsequent oral anti-coagulant control.

Adult↗
PubMed1998

Screening for osteoporosis in Crohn's disease. A detailed evaluation of calcaneal ultrasound.

OBJECTIVES: To compare calcaneal broadband ultrasonic attenuation (BUA) and velocity of sound (VOS) in patients with Crohn's disease with an age-matched control population. The validity of BUA as a screening tool for osteoporosis was evaluated and the relationship between BUA and previous fracture studied. DESIGN: Cross-sectional study. BACKGROUND: Since patients with Crohn's disease are at risk of osteoporosis and premature fracture, routine assessment of bone mineral density (BMD) is recommended. Quantitative ultrasound of the calcaneum is an inexpensive and radiation-free means of assessing bone density which also provides information on bone microstructure. METHODS: BUA (dB/MHz) and VOS (m/s) were measured at the calcaneum (CUBAclinical, McCue Ultrasonics, Winchester, UK) and compared with bone mineral density at the hip and lumbar spine measured by dual-energy X-ray absorptiometry (DEXA); 100 patients (42 men) with Crohn's disease and 52 age-matched healthy controls (23 men) were studied. RESULTS: BUA was significantly reduced in patients with Crohn's disease compared with age-matched controls [76.53 dB/MHz (+/-17.3) vs 87.29 dB/MHz (+/-17.9), difference in means = 10.76, 95% CI -16.67, -4.85, P = 0.0004] and was significantly associated with BMD at the spine (r = 0.49, 95% CI 0.32, 0.63, P< 0.0001) and femoral neck (r = 0.54, 95% CI 0.38, 0.67, P < 0.0001). In the diagnosis of osteoporosis (t score <-2.5) BUA had a sensitivity of 66.7% at the femoral neck, with a specificity of 85.6%; sensitivity of BUA at the spine was 75% with specificity 89%. CONCLUSION: Patients with Crohn's disease have reduced BUA compared with an age-matched control population. Calcaneal BUA is significantly associated with BMD at the hip and spine but the correlation is insufficient to recommend ultrasound as a screening tool for DEXA.

Absorptiometry, Photon↗
PubMed1997

Is histological examination of tissue removed by general practitioners always necessary? Before and after comparison of detection rates of serious skin lesions.

OBJECTIVES: To examine whether histological examination of all tissue removed by general practitioners in minor surgery increases the rate of detection of clinically important skin lesions, and to assess the impact of such a policy on pathologists' workload. DESIGN: Before and after comparison. SETTING: Stratified random sample of 257 general practitioner partnerships from the catchment areas of 19 English pathology laboratories. SUBJECTS: Tissue removed in minor surgery by general practitioners during the control period (September 1992 to February 1993) and intervention period (September 1993 to February 1994). INTERVENTION: General practitioners referred to their local pathology laboratory all solid tissue removed in all minor surgery, irrespective of their previous policy. MAIN OUTCOME MEASURES: Numbers of specimens referred for histology by general practitioners during intervention and control periods; numbers of primary malignant melanomas, non-melanoma malignancies, premalignant lesions, and benign lesions. RESULTS: 257/330 partnerships participated (response rate 78%). During the intervention period 5723 specimens were sent, compared with 4430 during the control period. The referral rate increased by an estimated 1.34 specimens per 1000 patient years (95% confidence interval 0.93 to 1.76, P < 0.0001). General practitioners sent 204 specimens that were malignant (including 16 malignant melanomas) in the control period and 188 that were malignant (including 15 malignant melanomas) during the intervention period (change in total number of malignancies, -1.0 per 100,000 patient years (-5.9 to 3.8, non-significant). CONCLUSIONS: The intervention was associated with a substantial increase in laboratory workload, all of which was accounted for by increases in non-serious lesions. This observation should be taken into account when considering the merits of a policy requiring histological examination in every case.

England↗
PubMed1997

Differing responses in blood pressure over 24 hours in normotensive women receiving oral or transdermal estrogen replacement therapy.

OBJECTIVE: To examine the effects of oral and transdermal estrogen replacement therapy (ERT) on ambulatory 24-hour blood pressure (BP) recordings. METHODS: In a nonrandomized, prospective study, 90 normotensive, oophorectomized women, ages 30-59 years, underwent ambulatory 24-hour BP measurements at study entry and after 3 and 6 months of either oral (n = 50) or transdermal (n = 40) ERT. RESULTS: In the women receiving transdermal estrogen, we observed a change in mean nighttime systolic BP of -4.2 mmHg (95% confidence interval [CI] -7.7, -0.7; P = .039) after 6 months, treatment. There was a change in mean daytime diastolic BP after 3 months (-3.3 mmHg; 95% CI -5.5, -0.9; P = .016) and 6 months (-4 mmHg; 95% CI-6.8, -1.2; P = .014), and in mean nighttime diastolic BP after 3 months (-3.8 mmHg; 95% CI -6.6, -0.9; P = .027) and 6 months (-4.4 mmHg; 95% CI -7.1, -1.7; P = .005). No significant BP changes were observed in the women taking oral estrogen. Although the statistical power to detect a change of 4 mmHg at the 5% significance level was 90% for diastolic BP, it was weaker for systolic BP (63%) in this group. However, in more than one-third of the women receiving either treatment, a statistically significant increase in BP was observed. CONCLUSIONS: Transdermal ERT was associated with a reduction in mean ambulatory BP, whereas oral treatment did not alter BP. Although the overall effect of estrogen was to lower BP, individual responses were variable, and BP increased in more than one-third of the women on either treatment. Therefore, long-term monitoring of ambulatory measurements may be required.

Administration, Cutaneous↗
PubMed1997

Rectal steroids suppress bone formation in patients with colitis.

BACKGROUND: The aetiology of bone loss in inflammatory bowel disease is multifactorial, but oral corticosteroids are an important contributory factor. Rectally administered steroids are widely used in patients with distal disease, but very little is known about their effect on bone metabolism. The aim of this study was to investigate the effect of a standard course of rectal prednisolone on biochemical markers of bone turnover. METHODS: In a longitudinal study of 10 patients, biochemical markers of bone turnover were measured before, during and after treatment with prednisolone metasulphobenzoate (Predfoam, Pharmax Ltd) 20 mg twice daily for 2 weeks. Bone formation markers measured were serum osteocalcin (BGP), bone-specific alkaline phosphatase (BALP) and procollagen carboxy-terminal propeptide (PICP). Urinary deoxypyridinoline (dPyr) was measured to assess bone resorption. RESULTS: Disease activity scores improved during treatment (difference in mean Powell-Tuck score = 2.3 (+/-13.1), 95% CI: 0.11-4.48, P = 0.04). There was a significant fall in BALP (P = 0.02) during treatment, and a rapid but non-significant fall in BGP (P = 0.19). PICP (0.42), and urinary dPyr (0.30) did not change significantly during treatment. CONCLUSIONS: Following a standard 2-week course of rectal prednisolone metasulphobenzoate, we observed a significant fall in bone-specific alkaline phosphatase activity. These results suggest that bone formation is suppressed in patients with distal colitis treated with pharmacological doses of rectal steroids.

Administration, Rectal↗
PubMed1997

The relation of hand skin-fold thickness to bone mineral density in patients with Crohn's disease.

OBJECTIVES: In healthy postmenopausal women, the association of skin-fold thickness (SFT) with bone mineral density (BMD) is well described, and a low SFT is a useful predictor of osteoporosis. In this study the association between hand SFT and BMD in patients with Crohn's disease was assessed; and the potential for hand SFT as a screening test for osteoporosis evaluated. DESIGN/METHODS: In a cross-sectional study, BMD was measured at the hip and lumbar spine by dual energy x-ray absorptiometry (DEXA). SFT was measured on the dorsum of the right hand using Holtain Tanner Whitehouse calipers. One hundred and seventeen patients (48 male) with Crohn's disease and 50 (25 male) controls were studied. RESULTS: There was a significant correlation between hand SFT and BMD (expressed as t scores) at all four measured sites (lumbar spine r = 0.41, P < 0.0001, 95% CI 0.25-0.55, Ward's triangle r = 0.38, P < 0.0001, 95% CI 0.21-0.53, trochanter r = 0.33, P < 0.0001, 95% CI 0.16-0.48, femoral neck r = 0.38, P < 0.0001, 95% CI 0.21-0.53). On stepwise regression analysis, the association remained significant after correcting for age, weight, menstrual status and current steroid use (P < 0.05). Hand SFT was significantly lower in patients with Crohn's disease than controls (difference in means 0.51 mm, 95% CI 0.3-0.72, P < 0.0001). Mean hand SFT was significantly lower in patients with osteoporosis compared to patients with normal BMD (difference in means 0.74 mm, 95% CI 0.33-1.15, P < 0.001), as was that of osteopenic patients compared to patients with normal BMD (difference in means 0.28 mm, 95% CI 0.01-0.55, P < 0.05). In the diagnosis of osteoporosis, the sensitivity of hand SFT ranged from 29% to 93%, with specificities of 54% to 95%. CONCLUSIONS: Hand SFT is independently associated with BMD in Crohn's disease and is lower than in age-matched healthy subjects. Hand SFT in combination with other easily measurable confounding variables might be useful in screening for osteoporosis in patients with Crohn's disease.

Adult↗
PubMed1996

A Bayesian approach to Weibull survival models--application to a cancer clinical trial.

In this paper we outline a class of fully parametric proportional hazards models, in which the baseline hazard is assumed to be a power transform of the time scale, corresponding to assuming that survival times follow a Weibull distribution. Such a class of models allows for the possibility of time varying hazard rates, but assumes a constant hazard ratio. We outline how Bayesian inference proceeds for such a class of models using asymptotic approximations which require only the ability to maximize the joint log posterior density. We apply these models to a clinical trial to assess the efficacy of neutron therapy compared to conventional treatment for patients with tumours of the pelvic region. In this trial there was prior information about the log hazard ratio both in terms of elicited clinical beliefs and the results of previous studies. Finally, we consider a number of extensions to this class of models, in particular the use of alternative baseline functions, and the extension to multi-state data.

Bayes Theorem↗
PubMed1996

The beneficial effects of oral nifedipine on cyclosporin-treated renal transplant recipients--a randomised prospective study.

The aim of this study was to test the hypothesis that nifedipine will improve graft survival in cyclosporin A (CyA)-treated renal transplant recipients. One hundred and forty-seven patients were randomised to one of three regimens. Group A received CyA, 7 mg/kg per day, and prednisolone; group B followed the same regimen as group A plus oral nifedipine and group C received CyA, 4 mg/kg per day, prednisolone and azathioprine. Calcium channel blockers were avoided in groups A and C. The crude 2-year (P = 0.0223) and 4-year (P = 0.0181) graft survival was significantly better in group B (86% and 81%, respectively) than in group A (75% and 63%, respectively). Delayed initial function was seen least frequently in group B (10.2%) compared to groups A (31%) and C (28%; P < 0.01). Group B also experienced fewer rejection episodes than groups A and C (P < 0.05). We conclude that the combination of oral nifedipine and CyA significantly improves initial graft function, rejection frequency and long term graft survival.

Administration, Oral↗
PubMed1996

Endometrial responses to hormone replacement therapy: the bleeding pattern.

Little information is available concerning the response of the endometrium to exogenous sex steroid therapy, particularly in the post-menopausal state. In this study we examined the variability of the bleeding pattern in 103 post-menopausal women receiving cyclical sequential combined hormone replacement therapy (HRT) over 6 months. All patients kept menstrual diary cards to record the onset, duration and subjective assessment of the severity of bleeding. We defined a cycle as starting from the commencement of treatment till the day of onset of bleeding. Two groups were identified amongst 99 women who experienced bleeding: those with a mean cycle length of 29 or more days (late bleeders, n = 50) and those with shorter mean cycle length (early bleeders, n = 49). The former were characterized by less variability in cycle length and bleeding that was of shorter duration. Four women experienced no bleeding. There were no significant differences between the two groups in age, year since the menopause, weight, height, body mass index (BMI), parity, or in the previous use of HRT. The only significant difference was in their smoking habits. This suggests a possible link of a hypo-oestrogenic state to poor cycle control.

Adult↗
PubMed1996

A new decision model for cost-utility comparisons of chemotherapy in recurrent metastatic breast cancer.

In the absence of comparative clinical and pharmacoeconomic trial data for docetaxel versus paclitaxel as second-line therapy for patients with anthracycline-resistant metastatic breast cancer, a computer-based decision-analysis model was designed to evaluate the comparative utility to patients of these two taxoids. The model used the Markov process to analyse disease states (response, stable disease, progressive disease) and toxicities (acute, cumulative) for each treatment during the period from commencement of up to six 3-weekly cycles of chemotherapy, to death. A cost-utility analysis was carried out using the model, with a probability, a cost and a utility determined for each health state. Response rates were obtained from clinical trial data supplemented by expert clinical opinion. Costs were taken from UK national databases and published sources and the published UK prices of docetaxel and paclitaxel. Utilities for the various health states were established by use of standard gamble and visual analogue methods assessed by 30 oncology nurses in the UK who were acting as proxy patients. The results of the model showed that response rate is the key parameter determining the utility and cost utility of treatments for metastatic breast cancer. Although the total per-patient cost associated with docetaxel was marginally higher than that for paclitaxel (8233 pounds vs 8013 pounds), the higher response rate associated with docetaxel produced an improvement in utility to the patient at an incremental healthcare cost that is acceptable according to available defined limits. Sensitivity analyses revealed that, although the model was sensitive to changes in response rate and drug costs, the cost-utility ratio for docetaxel versus paclitaxel varied within acceptable limits in response to all likely changes in key parameters. In summary, in the base case used in this model, docetaxel produces a substantially larger utility benefit than paclitaxel, at a small additional cost per QALY gained (equivalent to 7 pounds per additional day of perfect health).

Breast Neoplasms↗
PubMed1995

Thrombocytopenia in dogs induced by granulocyte-macrophage colony-stimulating factor: increased destruction of circulating platelets.

Administration of recombinant canine granulocyte-macrophage colony-stimulating factor (rcGM-CSF) to normal dogs in previous studies induced an increase in peripheral blood neutrophils and a dose-dependent decrease in platelet counts. In six dogs that received the highest tested dose of rcGM-CSF (50 micrograms/kg/d) for a minimum of 12 days, the mean nadir of the platelet count was 46,000/microL (range, 4,000 to 91,000/microL) on day 9 +/- 1.1 after starting therapy, compared with a mean baseline platelet count of 398,000/microL (range, 240,000 to 555,000/microL). In three dogs, survival of autologous 111In-labeled platelets was reduced from a mean of 4.9 days to 1.3 days during the administration of rcGM-CSF. Biodistribution studies with gamma camera imaging indicated that there was an increase in mean hepatic uptake during the administration of rcGM-CSF, from 15% to 44% of the total injected 111In-labeled platelets at 2 hours, whereas splenic uptake was not significantly changed. In contrast, in two evaluable dogs who were recipients of 111In-labeled platelets from matched allogeneic donors receiving rcGM-CSF, platelet survival was not reduced and no increased hepatic uptake was noted. A third dog became alloimmunized to the matched donor platelets and was not evaluable. Immunohistologic studies of liver and spleen were performed with monoclonal antibodies specific for canine gpIIb/IIIa and P-selectin in dogs treated with rcGM-CSF and compared with untreated controls. On treatment, a marked reduction of platelets in the red pulp of the spleen was evident, and in general, the presence of platelet antigen in the liver was unchanged. Therefore, platelets were not being sequestered, but destroyed in the liver and spleen. The platelet antigens, P-selectin and gpIIb/IIIa, were identified in association with Kupffer cells in the liver, but no difference in the number of distribution of these Kupffer cells was found between controls and rcGM-CSF-treated dogs. In the spleen during rcGM-CSF treatment, most platelet antigens were associated with large mononuclear cells in the marginal zone. During administration of rcGM-CSF, CD1c and CD11c expression was increased on Kupffer cells. Platelet P-selectin expression and binding of leukocytes to circulating platelets were unchanged from baseline studies with rcGM-CSF treatment. In conclusion, during the administration of rcGM-CSF to dogs, a local process in the liver and spleen is induced resulting in thrombocytopenia.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1995

Abnormal uterine bleeding on hormone replacement: the importance of intrauterine structural abnormalities.

OBJECTIVE: To examine the importance of submucous myomas and endometrial polyps before and after menopause and in abnormal withdrawal bleeding on hormone replacement therapy (HRT). METHODS: Between May 1991 and May 1993, women presenting with abnormal withdrawal bleeding on HRT (n = 106), menstrual problems in pre-menopause (n = 92), or postmenopausal bleeding (n = 33) underwent diagnostic outpatient hysteroscopy for the presence of intrauterine structural abnormalities. The findings were compared with a control group of post- and perimenopausal women without bleeding problems (n = 183). RESULTS: When compared with women who had normal uterine cavities, the presence of submucous myomas was associated with a threefold increase in the risk of abnormal menstrual bleeding in premenopausal women (odds ratio [OR] 3.34, 95% confidence interval [CI] 1.77-6.43; P < .001) and a twofold increase in the risk of abnormal withdrawal bleeding in post- and perimenopausal women (OR 2.4, 95% CI 1.25-4.53; P = .004). This did not seem to be related to the number of myomas detected. The frequency of endometrial polyps was not found to be significantly higher in women who had menstrual disorders or abnormal withdrawal bleeding on HRT. Postmenopausal bleeding without hormonal stimulation was not significantly associated with submucous myomas or polyps. CONCLUSION: As increasingly more women request HRT, bleeding problems presenting pre-menopause can no longer be expected to resolve "naturally" after menopause. In the presence of submucous myomas, these women will continue to have a higher risk of abnormal withdrawal bleeding when treated with hormone replacement, whereas endometrial polyps are not associated with an increased bleeding risk. Hysteroscopic assessment of the uterine cavity and subsequent counseling as to the risk of heavy or prolonged bleeding will be helpful in their future management and may improve compliance.

Adult↗
PubMed1994

Quality of life and survival with continuous hepatic-artery floxuridine infusion for colorectal liver metastases.

Very few patients with liver metastases from colorectal cancer can be cured. We have investigated whether a treatment to slow the growth of liver metastases, hepatic-artery infusion of floxuridine, improves palliation in this setting. In a randomised study of 100 patients, we compared quality of life and survival in patients who received hepatic-artery infusion of floxuridine and in those who received conventional symptom palliation. 95% of control patient survival time was spent with normal quality-of-life scores, which suggests that the aim of treatment should be to prolong normal-quality survival rather than merely to sustain quality of life. There was a significant prolongation (p = 0.03) in overall survival in floxuridine-treated patients compared with controls (median 405 vs 226 days). There were similar significant prolongations in normal-quality (ie, normal symptom scores) survival for physical symptoms (p = 0.04), anxiety (p = 0.04), and depression (p = 0.04). This survival benefit was associated with significant reductions in metastasis size on computed tomography (p = 0.001) and in serum carcinoembryonic antigen concentration (p = 0.006) in floxuridine-treated patients. There was no evidence of treatment-related hepatotoxicity as assessed by serum aspartate aminotransferase and bilirubin measurements. This is the first demonstration that survival can be prolonged with normal quality of life in patients with colorectal liver metastases. We conclude that hepatic-artery floxuridine infusion can be recommended for suitable patients.

Anxiety↗
PubMed1994

Simple Bayesian analysis in clinical trials: a tutorial.

In this tutorial paper we give a simple Bayesian analysis of data that arise in clinical trials. We consider the case when there are two treatment groups and the response in each group can be assumed to be binomially distributed. We also assume that prior beliefs about the rate parameter in each group can be adequately expressed by a Beta distribution. Using such a model approximate posterior inferences can then be made about the odds ratio between the two groups. We illustrate this methodology by analyzing a randomized trial to assess the benefits of treating patients with carcinoma of the pelvic region (rectum, bladder, colon, cervix) using high-energy fast neutrons as opposed to conventional megavoltage x-rays (photons). In this trial there was prior information about the relative efficacy of neutron therapy based on the beliefs of 10 clinicians. Some of the deficiencies of this simple approach are high-lighted and other approaches to analysis indicated. The paper facilitates practical consideration of a Bayesian approach without the complexities that a fuller analysis necessitates.

Bayes Theorem↗
PubMed1993

Effect of organic solvents on in vitro human skin water barrier function.

Skin barrier disruption caused by organic solvents to human cadaver dermatomed skin was evaluated using an in vitro model system. Resultant changes in transepidermal water loss (TEWL), as measured with an evaporimeter, were recorded after topical application of either acetone, chloroform:methanol 2:1, hexane, hexane:methanol 2:3, or the control, water, for exposure times of 1, 3, 6, and 12 min. The resultant lipid/solvent mixture was removed and analyzed for its lipid content. The ability of the different solvents to induce changes in the skin's barrier function was assessed by comparing pre- to post-solvent exposure TEWL (delta TEWL). When compared to the controls, water and unexposed skin, chloroform:methanol 2:1 caused the greatest significant increase in TEWL, followed by hexane:methanol 2:3. Acetone and hexane showed no difference in TEWL from the controls. Besides solvent, exposure time was a significant independent variable for predicting delta TEWL, and the interaction of the two (exposure time and solvent type together) was the strongest predictor. Lipid analysis of the extracts revealed that all the solvents removed comparable quantities of the surface lipids (triglycerides, wax esters, squalene, cholesterol esters). Stratum lipids--ceramides, free fatty acids, and cholesterol--extracted by chloroform:methanol 2:1 and hexane:methanol 2:3 were comparable and significantly greater than those extracted by acetone and hexane. These two solvents failed, however, to induce comparable changes in TEWL, as chloroform:methanol 2:1 induced a significantly greater delta TEWL than hexane:methanol 2:3. Additionally, no individual lipid class extracted by either chloroform:methanol 2:1 or hexane:methanol 2:3 proved to be a significant or accurate variable for predicting delta TEWL. This suggests that the mechanism by which topical chloroform:methanol 2:1 and hexane:methanol 2:3 exposure induce a delta TEWL involves more than pure lipid extraction.

Adolescent↗
PubMed1992

Protection of macaques against SIV infection by subunit vaccines of SIV envelope glycoprotein gp160.

Simian immunodeficiency virus (SIV) is a primate lentivirus related to human immunodeficiency viruses and is an etiologic agent for acquired immunodeficiency syndrome (AIDS)-like diseases in macaques. To date, only inactivated whole virus vaccines have been shown to protect macaques against SIV infection. Protective immunity was elicited by recombinant subunit vaccines. Four Macaca fascicularis were immunized with recombinant vaccinia virus expressing SIVmne gp160 and were boosted with gp160 produced in baculovirus-infected cells. All four animals were protected against an intravenous challenge of the homologous virus at one to nine animal-infectious doses. These results indicate that immunization with viral envelope antigens alone is sufficient to elicit protective immunity against a primate immunodeficiency virus. The combination immunization regimen, similar to one now being evaluated in humans as candidate human immunodeficiency virus (HIV)-1 vaccines, appears to be an effective way to elicit such immune responses.

Animals↗