Thyroidal hemiagenesis

Three cases of thyroidal hemiagenesis have been reported. The patients were euthyroid and presented with adenomatous goiters; one uninodular and the others multinodular in the contralateral lobe. In two cases the diagnosis was established by the thyroid stimulation test and confirmed at operation. In one case, this test was not performed and the hemiagenesia was discovered at routine surgical exploration of the scintigraphically absent lobe. From our cases and review of the literature we have concluded that the anomaly is usually discovered while searching for a contralateral pathologic abnormality, a thyroid stimulation test is essential for a preoperative suspicion, it occurs more frequently among women and in the left lobe, and ours are the first cases reported from Spain.     

Sustained release of heparin from polymeric particles for inhibition of human vascular smooth muscle cell proliferation

Vascular smooth muscle cell (SMC) growth plays an important role in atherosclerosis, restenosis and venous bypass graft disease. With systemic drug administration no effective therapy for restenosis and venous bypass graft disease is available. This could be due to low local concentrations of the drugs at the target site. A directed delivery of drugs to tissues with a sustained release system during percutaneous transluminal coronary angioplasty (PTCA) or during bypass surgery could provide high concentrations of drugs at the target site and avoid systemic side effects. In the present study heparin was encapsulated by spray-drying into biodegradable poly( -lactic-co-glycolic acid) (PLGA) to obtain a system for prolonged drug release. SMC were cultured from saphenous vein explants obtained from patients undergoing coronary bypass surgery. Cell proliferation was measured by [³H]thymidine incorporation. Heparin release from PLGA 50:50 microspheres in an isoosmolar PBS buffer (pH=7.4) showed a triphasic profile with an initial burst (completed after 24 h), a dormant period and a final stage with increased release rate, which lasted about 10–14 days. Cell proliferation as measured by [³H]thymidine incorporation was markedly stimulated by platelet-derived growth factor-BB (PDGF-BB) (5 ng/ml) or serum (5%). Proliferation of SMC was equally reduced (50%; P<0.05; n=9–11) by native heparin or heparin released from PLGA microspheres, while PLGA microspheres without heparin loading had no effect on [³H]thymidine incorporation in human SMC. Similar results were also obtained when SMC were stimulated with 5% serum instead of PDGF-BB (50%; P<0.05; n=6). Thus, heparin encapsulated into PLGA microspheres was released over a prolonged period of time and thereby effectively reduced human SMC proliferation stimulated either with PDGF or serum. Biodegradable PLGA microspheres may also be used to encapsulate other antiproliferative agents and provide a new approach for local drug delivery after PTCA. This may help to prevent restenosis after PTCA or to reduce graft disease after coronary bypass graft surgery.     

Adjuvant tamoxifen in postmenopausal breast cancer: Preliminary results of a randomized trial

Summary Between May 1978 and March 1982, 179 postmenopausal women with operable breast cancer were randomized to receive either adjuvant tamoxifen, 40 mg daily for three years (TAM group), or no further treatment (controls).The difference in five-year survival rates (61% in the control group, 72% in the TAM group) was not statistically significant. However, there was a significant improvement in disease-free survival in the TAM group (61%) relative to the controls (44%) (p = 0.008). In estrogen receptor positive patients, tamoxifen improved both the disease-free rate (47% controls, 80% with tamoxifen) and the survival rate (63% to 83%). Similar results were observed in progesterone receptor positive patients. In patients that were estrogen receptor negative, tamoxifen modified neither the survival rate nor the disease-free interval.     

Intrinsic positive end-expiratory pressure in Acute Respiratory Distress Syndrome (ARDS) Network subjects

OBJECTIVE: We tested the hypothesis that subjects randomized to the 6 mL/kg predicted body weight tidal volume study group of the National Institutes of Health Acute Respiratory Distress Syndrome (ARDS) Network study had higher levels of intrinsic positive end-expiratory pressure (PEEP) than subjects randomized to the 12 mL/kg predicted body weight tidal volume study group. DESIGN: Secondary analysis of a subgroup from a randomized controlled trial. SETTING: Hospitals located in San Francisco, CA, and Seattle, WA. PATIENTS: Eighty-four patients enrolled in the ARDS Network tidal volume trial in San Francisco, CA, and Seattle, WA, with records of measurement of intrinsic PEEP. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Intrinsic PEEP was assessed a median of six times over the first 48 hrs of ARDS Network protocol ventilation in study subjects, with no significant difference in number of measurements between subjects randomized to the tidal volume protocol of 6 mL/kg compared with 12 mL/kg. We found that intrinsic PEEP was higher among subjects randomized to the 6 mL/kg protocol, with a median intrinsic PEEP of 1.3 cm H2O (interquartile range, 0-3.1 cm H2O), compared with a median intrinsic PEEP of 0.5 cm H2O (interquartile range, 0-1.5 cm H2O) among subjects randomized to 12 mL/kg (p = .029). There was no difference in total PEEP between the study groups. CONCLUSIONS: In a subgroup of ARDS Network subjects, intrinsic PEEP was statistically significantly higher in subjects randomized to the 6 mL/kg protocol than those in the 12 mL/kg study group. The amount of intrinsic PEEP was very low in both study groups, and difference of median intrinsic PEEP between the groups was <1 cm H2O. It is unlikely that the difference in intrinsic PEEP between the study groups was clinically important in the ARDS Network study of low tidal volume ventilation.     

The accuracy of transcranial Doppler to detect vasospasm in patients with aneurysmal subarachnoid hemorrhage

OBJECTIVES. To examine the accuracy of transcranial Doppler to detect cerebral vasospasm in a patient population with aneurysmal subarachnoid hemorrhage. DESIGN. Prospective blind comparison of transcranial Doppler with cerebral angiography. Diagnostic accuracy of transcranial Doppler was assessed using receiver operating characteristic (ROC) analysis and likelihood ratios. Sensitivity and specificity were calculated using directly measured middle cerebral artery diameter as reference standard. SETTING. Intensive Care Unit of a large university teaching hospital. PATIENTS AND PARTICIPANTS. Twenty-two patients with subarachnoid hemorrhage were included. Patients underwent angiography on admission and after 8 days to diagnose vasospasm and were defined as having clinical vasospasm, angiographic vasospasm, or no vasospasm. MEASUREMENTS AND RESULTS. Sensitivity and specificity were 1.00 and 0.75 for angiographic vasospasm and both equal to 1.00 for clinical vasospasm diagnosis. A transcranial Doppler mean velocity threshold value of 100 cm/s for angiographic vasospasm and 160 cm/s for clinical vasospasm detection were chosen by ROC analysis. CONCLUSIONS. A Transcranial Doppler mean velocity threshold of 160 cm/s, calculated by the ROC analysis, accurately detects clinical vasospasm. A daily transcranial Doppler examination performed by a trained operator should be routinely used to provide early identification of patients at high risk and to orient therapeutic decisions.     

Randomized Trial of Trimethoprim-Sulfamethoxazole versus Pyrimethamine-Sulfadiazine for Therapy of Toxoplasmic Encephalitis in Patients with AIDS

The aim of the present pilot study was to compare the efficacy and safety of trimethoprim (TMP) and sulfamethoxazole (SMX) with those of the standard therapy pyrimethamine (P)-sulfadiazine (S) for the treatment of toxoplasmic encephalitis in patients with AIDS. This was a pilot, multicenter, randomized, and prospective study. Patients were randomly assigned to receive TMP (10 mg/kg of body weight/day) and SMX (50 mg/kg/day) or P (50 mg daily) and S (60 mg/kg/day) as acute therapy (for 4 weeks) and then as maintenance therapy for 3 months at half of the original dosage. Seventy-seven patients were enrolled and randomized to the study: 40 patients were treated with TMP-SMX and 37 were treated with P-S. There was no statistically significant difference in clinical efficacy during acute therapy. In contrast, patients randomized to TMP-SMX appeared more likely to achieve a complete radiologic response after acute therapy. Adverse reactions were significantly more frequent in patients treated with P-S, and skin rash was the most common adverse event noted in these patients. In conclusion, the results of the study suggest that TMP-SMX appears to be a valuable alternative to P-S, in particular in patients with opportunistic bacterial infections.     

Prevalence of intra-abdominal hypertension in critically ill patients: a multicentre epidemiological study

Objective Although intra-abdominal hypertension (IAH) can cause dysfunction of several organs and raise mortality, little information is available on the incidence and risk factors for IAH in critically ill patients. This study assessed the prevalence of IAH and its risk factors in a mixed population of intensive care patients.Design A multicentre, prospective 1-day point-prevalence epidemiological study conducted in 13 ICUs of six countries.Interventions None.Patients Ninety-seven patients admitted for more than 24 h to one of the ICUs during the 1-day study period.Methods Intra-abdominal pressure (IAP) was measured four times (every 6 h) by the bladder pressure method. Data included the demographics, medical or surgical type of admission, SOFA score, etiological factors such as abdominal surgery, haemoperitoneum, abdominal infection, massive fluid resuscitation, and ileus and predisposing conditions such as hypothermia, acidosis, polytransfusion, coagulopathy, sepsis, liver dysfunction, pneumonia and bacteraemia.Results We enrolled 97 patients, mean age 64±15 years, 57 (59%) medical and 40 (41%) surgical admission, SOFA score of 6.5±4.0. Mean IAP was 9.8±4.7 mmHg. The prevalence of IAH (defined as IAP 12 mmHg or more) was 50.5 and 8.2% had abdominal compartment syndrome (defined as IAP 20 mmHg or more). The only risk factor significantly associated with IAH was the body mass index, while massive fluid resuscitation, renal and coagulation impairment were at limit of significance.Conclusion Although we found a quite high prevalence of IAH, no risk factors were reliably associated with IAH; consequently, to get valid information about IAH, IAP needs to be measured.