Simultaneous Serum Research Articles

35-Year-Old Woman With Cough, Fever, and Anorexia

35-Year-Old Woman With Cough, Fever, and Anorexia

Dermal bilirubin kinetics during phototherapy in term neonates.

To investigate dermal bilirubin kinetics during phototherapy in the presence of neonatal indirect hyperbilirubinaemia. 33 neonates with non-haemolytic indirect hyperbilirubinaemia, who required phototherapy, were included in the study. Phototherapy modules containing four normal and four blue fluorescent lamps were used during the study. The transcutaneous bilirubin index (TcBI) was measured in an area of the forehead covered by a 2.5 cm diameter opaque patch and a nearby exposed site. The TcBI obtained from patched and unpatched areas and simultaneous serum bilirubin (SB) concentrations were measured before the start of phototherapy and after 6, 12, 18, 30, 42 and 66 h of phototherapy. SB concentration and the TcBI from the unpatched area decreased significantly during the first 6 h of exposure, while the TcBI obtained from the patched area decreased significantly after 12 h. The TcBI from the unpatched area was consistently lower than that from the patched area during phototherapy. After the onset of phototherapy, there was a weak, non-significant correlation between SB concentrations and the TcBI from patched and unpatched areas. Phototherapy was effective for both patched and unpatched areas, but the rate of decline was slower in patched areas, only becoming significant in the second 6 h of treatment. There was no significant correlation between the levels of SB and TcBI after the onset of phototherapy, and therefore the use of TcBI cannot be recommended as a surrogate measure of SB.

Volume-selective 1H MR spectroscopy for in vivo detection of valproate in patients with epilepsy.

We performed volume-selective 1H MR spectroscopy (1H-MRS) on 12 patients on valproate monotherapy to detect valproate in vivo in the brain. We also acquired reference valproate spectra in vitro in subphysiological 15 g/l albumin solution in saline, in which valproate showed two resonance peaks at 0.7 and 1.2 ppm and a minimum detection threshold of 240 mg/l. In vivo 1H-MRS spectra in brain showed peaks between 0.6 and 1.6 ppm. Simultaneous serum valproate concentrations did not correlate with these integrated MRS peaks. On follow-up, changes in these signals also did not correlate with increasing serum valproate levels. The inconsistency of in vivo 1H-MRS signals at varying serum levels and the high detection levels in vitro suggest that valproate signals are missed in vivo because valproate is metabolised or strongly bound, presumably to brain macromolecules.

High serum YKL-40 level after surgery for colorectal carcinoma is related to short survival.

YKL-40 is a member of family 18 glycosyl hydrolases. YKL-40 is a growth factor and may stimulate migration of endothelial cells. YKL-40 may also play a role in inflammation and degradation of connective tissue. Elevated preoperative serum YKL-40 levels in patients with colorectal carcinoma are associated with a significantly poorer prognosis compared to patients with normal serum YKL-40. In the current study the authors evaluated the value of serum YKL-40 in monitoring patients with colorectal carcinoma. YKL-40 was determined by an in-house radioimmunoassay method in serum obtained pre- and postoperatively from 324 patients who underwent curative resection (Dukes Stage A: 47; B: 148; C: 119; and D: 10). The patients were followed with serum YKL-40 levels every 6 months postoperatively, and the median followup time was 82 months (range, 68-95). In that period 146 patients died. Serum YKL-40 was significantly decreased in the first postoperative blood sample in 62% of patients with high preoperative levels. In addition, patients with high serum YKL-40 (adjusted for age) six months after curative operation had significantly shorter survival times (P = 0.0002) and shorter relapse free intervals (P = 0.004) than patients with normal postoperative serum YKL-40. This result was independent of simultaneous serum carcinoembryonic antigen levels at six months. Analysis of survival by scoring serum YKL-40 as a time-dependent covariate in a Cox regression analysis showed that patients exhibiting elevated serum YKL-40 had an increased hazard for death within the following six months compared to those patients with normal serum YKL-40 level (hazard ratio [HR] = 9.6, 95% confidence interval [CI]: 6.0-15.5, P < 0.0001). Multivariate analysis including Dukes stage, age, gender, and tumor location as well as the time-dependent serum YKL-40 showed that high serum YKL-40 was an independent prognostic variable of survival (HR = 8.5, 95% CI: 5.3-13.7, P < 0.0001). These results suggest that determination of serum YKL-40 during followup of patients operated on for colorectal carcinoma might be useful for monitoring curatively resected patients.

Prolonged QTc intervals on the electrocardiograms of hospitalized malnourished adults

We investigated whether hospitalized malnourished adults would have longer QTc intervals on their electrocardiograms (ECGs) than non-malnourished adults. Seventy-five consecutive adults hospitalized in the Internal Medicine wards of our teaching hospital were prospectively studied. Main diagnoses, anthropometry, including body mass index (kg/m 2), ECGs, and simultaneous serum levels of sodium, potassium, magnesium, phosphorus, and calcium were recorded. All QT intervals on ECGs were measured in a semiautomatic image analysis system; and QTc intervals were determined with the Bazett formula. Protein-energy malnutrition (PEM) was diagnosed with body mass index below 18.5 kg/m 2. There was no statistical difference between malnourished ( n = 30) and non-malnourished ( n = 45) with regard to age (40.7 ± 18.9 y versus 41.4 ± 16.2 y), male predominance (66.7% versus 80%), or associated diagnoses. Compared with non-malnourished, malnourished patients had higher percentages of positive C-reactive protein (66.7 versus 23.8%), lower serum levels of albumin (2.51 ± 0.89 g/dL versus 3.41 ± 0.74 g/dL) and potassium (3.64 ± 0.65 mEq/L versus 4.12 ± 0.65 mEq/L), and increased QTc lengths on ECGs (0.423 ± 0.033 ms versus 0.396 ± 0.031 ms). Malnourished adults hospitalized in general clinical wards are more likely to have longer QTc intervals on their ECGs, a phenomenon possibly linked to malnutrition and associated electrolyte disturbances.

Pseudohyperkalemia Secondary to Postsplenectotny Thrombocytosis

Hyperkalemia is a regularly encountered electrolyte abnormality. Less commonly recognized is pseudohyperkalemia. In vitro clotting results in the release of potassium from the formed elements of blood; this falsely elevates the serum potassium concentration. Usually attributed to thrombocytosis, leukocytosis, or hemolysis it is rarely reported in the postsplenectomy trauma patient. A 49-year-old man underwent splenectomy for a grade IV splenic injury. He developed an elevated serum potassium on postoperative day 16. His renal function remained normal, and an active search for causes of hyperkalemia failed to delineate a source for his elevated potassium. Pseudohyperkalemia was proposed as an etiology and confirmed by analyzing simultaneous serum (5.9 mEq/L) and plasma potassium levels (3.9 mEq/L). The serum potassium showed a concomitant rise with the evolution of the patient's postsplenectomy thrombocytosis. This is a case report of our patient and a literature review of this rarely reported and underestimated cause of a potentially serious electrolyte abnormality. We found through our patient that pseudohyperkalemia does occur in the postsplenectomy population and that this should be included in the differential diagnosis of any patient with an elevated serum potassium level and thrombocytosis.

CASE REPORT

A29-year-old woman was admitted under the care of the general surgeons with a 3-week history of increasing colicky epigastric and retrosternal pain with severe nausea, profuse bile-stained vomiting, constipation and weight loss of 1.5 stone. In contrast, for the preceding 6 months she had been suffering from weight gain, ‘indigestion’, malaise, lethargy and syncopal attacks. There was no previous history of note and she had had two uneventful deliveries 3 and 5 years previously. On examination, she looked unwell, was severely dehydrated and apyrexial. Her skin was pale with a yellow tinge. Mucous membranes were pink and sclera were not pigmented. Her pulse was 92 beats per minute and her blood pressure was 93/51 mmHg. Abdominal examination revealed epigastric tenderness with guarding, but no rebound tenderness. There was no abdominal distension or succussion splash. She had marked abdominal striae which were pigmented. Laboratory results were as follows: haemoglobin 15.9 g/dl (normal range (NR) 11.0−16.5 g/dl), white cell count 10.8×109/litre (NR 3.5−11.0×109/litre), neutrophils 5.7×109/litre (NR 1.5−7.5×109/litre), haematocrit 0.478 (NR 0.36−0.45), sodium 133 mmol/litre (NR 135−146 mmol/litre), potassium 4.1 mmol/litre (NR 3.6−5 mmol/litre), urea 5.9 mmol/litre (NR 2.6−6 mmol/litre), creatinine 153 mmol/litre (NR 62−124 mmol/litre), amylase 70 U/litre (NR &lt;300 U/litre), aspartate transaminase 35 IU/litre (NR 0−40 IU/litre), alkaline phosphatase 43 IU/litre (NR 40−105 IU/litre), bilirubin 21 mmol/litre (NR 0−17mmol/litre), calcium 2.53 mmol/litre (NR 2.12−2.62mmol/litre), albumin 41g/litre (NR 32−45g/litre), urine dipstick negative for blood and protein, and pregnancy test negative. Abdominal and chest X-rays were unremarkable. An ultrasound scan of the biliary tract revealed a solitary gall stone with a normal calibre common bile duct. Surgical differential diagnoses included biliary colic or peptic ulceration but because of the low sodium in the presence of clinical and biochemical/haematological dehydration a diagnosis of adrenocortical failure was considered. A random cortisol was performed at presentation with a value of 40 nmol/litre. A short synacthen test revealed a basal cortisol of 41 nmol/litre and virtually no response to adrenocorticotrophic hormone (ACTH) with cortisol values of 43 nmol/litre at 30 minutes and 51nmol/litre at 60 minutes confirming adrenocortical failure. A simultaneous serum ACTH was grossly elevated at 834 ng/litre (NR 0−50 ng/litre), showing this to be primary adrenocortical failure and thus Addison's disease. Subsequent investigations showed her to be hypothyroid with a thyroid-stimulating hormone level of 74 mU/litre (NR 0.35−5.5 mU/litre) and free thyroxine (T4) of 5 pmol/litre (NR 10−22 pmol/litre) and to have circulating antithyroid microsomal and adrenal antibodies.

GIANT SPONTANEOUS URINOMA DRAINING FROM THE SCROTAL WALL

An 18-year-old male presented elsewhere with right abdominal pain and swelling, right scrotal pain and fluid discharge from a scrotal wound. On physical examination the patient appeared unhealthy and the right abdomen was asymmetrically swollen with a firm nontender mass .A3c m. vertical incision was noted on the right scrotum as well as abundant discharge of clear fluid from this wound. Abdominal discomfort and pain recurred 1 month later. A week later the right abdomen was enlarged, and the right scrotum became red, tender and swollen. The scrotum was incised elsewhere and the diagnosis was right scrotal abscess. The purulent discharge changed within days and large quantities of clear fluid began to drain from the scrotal incision. Simultaneously daily urine output decreased and abdominal swelling increased. The patient was referred to our institution. Laboratory evaluation demonstrated a creatinine of 8.43 mg./dl. (normal 0.5 to 1.4), urea 251 mg./dl. (normal 10 to 50), erythrocyte sedimentation rate 110 mm. per hour and leukocyte count 18,400/mm.3 Urine output was about 100 cc/24 hours and urinalysis showed pyuria. Computerized tomography (CT) revealed an atrophic left kidney and right hydronephrosis with stones in the right kidney and ureter. An immense cystic mass probably originating from the right kidney occupied the right retroperitoneum and extended into the right scrotum through the inguinal canal (fig. 1). The differential diagnosis at this time was tuberculosis, hydatid disease, hydrocele en bisac and spontaneous urinoma. Serological evaluation for tuberculosis and hydatid disease was negative. Radiopaque material was avoided due to high serum creatinine. The mass was punctured under ultrasound guidance, and cytological and biochemical studies were performed. The creatinine level of the fluid was 39.5 mg./dl., which was 5-fold that of the simultaneous serum level. Thus, the diagnosis of spontaneous urinoma was confirmed. A double pigtail ureteral catheter was inserted on the right side. General condition improved within days, daily urine output increased, and blood urea and creatinine returned to normal. Drainage from the scrotal incision ceased and abdominal swelling disappeared 4 days after catheter insertion. Excretory urography on day 10 postoperatively showed a bifid pelvis and normal right kidney function, the double pigtail catheter in situ, and lower caliceal and mid ureteral stones. The urinoma was followed by CT. Complete resolution of the urinoma was noted on CT 4 months postoperatively (fig. 2). Stones were treated with extracorporeal shock wave lithotripsy followed by catheter removal. The patient was well and without complaints at 5-month followup.

IgG2 immunodeficiency: association to pediatric patients with bacterial meningoencephalitis

An IgG subclass deficiency is often associated with bacterial infections. We studied four pediatric patients suffering from meningoencephalitis, two of them due to Streptococcus pneumoniae and two due to Haemophilus influenzae type b. Simultaneous diagnostic serum and cerebrospinal fluid samples were taken during income. The four subclasses of IgG and albumin were quantified in both biologic fluids by radial immunodiffusion. Very low levels of seric IgG2 with non detectable cerebrospinal fluid IgG2 were found in the patients. No intrathecal IgG subclass synthesis was found in two patients. One patient with S. pneumoniae had IgG3 intrathecal synthesis. Intrathecal IgG1, IgG3 and IgG4 synthesis was found in one patient suffering from H. influenzae according with reibergrams. Substitutive therapy with intravenous gammaglobulin was given to the patients as part of the treatment.

Simultaneous Serum Assays of Lipase and Interleukin-6 for Early Diagnosis and Prognosis of Acute Pancreatitis

There are no systems for the rapid diagnosis and prognosis of acute pancreatitis in the Emergency Department. Our aim was to evaluate whether the combined use of serum lipase and interleukin-6 or serum lipase and C-reactive protein is able to simultaneously establish both the diagnosis and the prognosis of acute pancreatitis. Eighty patients with acute abdomen were studied on admission to the Emergency Room. Forty patients had nonpancreatic acute abdomen, and 40 had acute pancreatitis (25 had mild acute pancreatitis and 15 had severe pancreatitis). Forty healthy subjects comparable for sex and age were also studied as controls. Lipase, interleukin-6, and C-reactive protein were determined on serum in all subjects. Using lipase to discriminate between patients with nonpancreatic acute abdomen and patients with acute pancreatitis (cutoff values ranging from 419 to 520 U/L), one patient with acute pancreatitis was not identified correctly. To discriminate between patients with severe acute pancreatitis and those with mild pancreatitis in the remaining 39 patients, interleukin-6 (cutoff value, <3.7 microgram/L) had a sensitivity of 100% (15 of 15) and a specificity of 83% (20 of 24); 75 of 80 (94%) patients were classified correctly. C-reactive protein (cutoff values ranging from 6 to 7 mg/L) showed a lower prognostic efficiency than interleukin-6: sensitivity of 87% (13 of 15) and specificity of 46% (11 of 24). Sixty-four of 80 patients (80%) were classified correctly. The area under the ROC curve for interleukin-6 (0.911 +/- 0.049) was significantly (P = 0.013) greater than that for C-reactive protein (0.685 +/- 0.090). The combined use of serum lipase and interleukin-6 is useful in simultaneously establishing both the diagnosis and the prognosis of acute pancreatitis.

Plasma homocysteine levels and folate status in children with sickle cell anemia.

A sensitive inverse relationship between plasma homocysteine concentration and folate status has been demonstrated. Although children with sickle cell anemia (SCA) are at potential risk for folate deficiency, plasma homocysteine levels have not been reported in such patients. Therefore, a study was designed to assess plasma homocysteine levels as a marker of folate status. Plasma homocysteine concentrations were measured in 120 children with SCA (102 in steady state and 18 during an acute complication) who had never received supplemental folic acid. Folate status was directly assessed in 34 of these patients. Plasma homocysteine levels in the patients with SCA and control subjects were similar. The mean value +/- 1 SD was 5.8+/-2.5 micromol/L (range, 1.6 to 14.1 micromol/L) in the patients with SCA and 6.1+/-2.7 micromol/L (range, 1.7 to 15.3 micromol/L) in 73 pediatric control subjects. In a subpopulation of the study group (34 children), simultaneous serum folate, red cell folate, and total homocysteine concentrations were also measured. Their serum folate and red cell folate concentrations were normal: 12.4+/-10.0 nmol/L (range, 1 to 42 nmol/L) and 604+/-374.7 nmol/L (range, 205 to 1741 nmol/L), respectively. There was no correlation of plasma homocysteine concentration with various clinical or laboratory measures or with red cell folate concentration. Folate stores in children with SCA not receiving folic acid supplements are adequate despite an underlying hemolytic anemia.

Salivary estradiol and progesterone levels in conception and nonconception cycles in women: evaluation of a new assay for salivary estradiol

Objective: To determine the usefulness of salivary E 2 and progesterone for noninvasive assessment of ovarian function. Design: Prospective study of salivary hormone levels in women planning a pregnancy. Setting: Department of Obstetrics and Gynecology at Northwestern University Medical School in Chicago, Illinois. Patient(s): Fourteen women aged 23–39 years with regular menstrual cycles who were planning a pregnancy. Intervention(s): None. Main Outcome Measure(s): Salivary estradiol and progesterone concentrations. Result(s): The sensitivity of the E 2 assay is 2.0 pmol/L; the interassay coefficient of variation was 5.2% (mean value 17 pmol/L). Recovery of E 2 added to saliva was 106%. The correlation with simultaneous serum samples was 0.71. Menstrual cycle patterns contained a preovulatory depression and a midcycle surge. By comparison with nonconception cycles, the luteal phases of conception cycles had significantly elevated salivary E 2 within the first 5 days after ovulation. Salivary progesterone was significantly elevated but not until 10 days after ovulation. Conclusion(s): Salivary measurements of E 2 and progesterone can be used as noninvasive methods for assessment of ovarian function. Salivary specimens can be collected at home and brought to the laboratory for analysis, obviating the need for frequent phlebotomy. The sensitivity and precision of the salivary E 2 assay make it comparable with assays of serum E 2 for assessing changes in hormone levels.

Microtitre Plate and Assay Buffer Alter Detection of Antiphosphatidylethanolamine Antibodies in Lupus Anticoagulant Positive Plasma

The ELISA for detection of anti-phosphatidylethanolamine antibodies in patients with lupus anticoagulant was studied. The influence of microtitre plate types, antigen concentration, antibody dilution, and buffer system was evaluated. Human albumin in the blocking buffer gave greater numbers of positive plasma samples than bovine serum. Comparison of simultaneous plasma and serum samples showed only minor variation in binding characteristics.

Serum Leptin and Regional Cerebral Blood Flow during Exposure to Food in Obese and Normal-Weight Women

Leptin is an adipocyte-derived product of the ob gene thought to be involved in the regulation of eating. Receptors for leptin have been found in multiple regions in the brain. In particular, hypothalamic receptors seem to be of fundamental importance for the biological effects of leptin. However, the association of leptin with cerebral function in humans has not been studied. Therefore, in order to assess the possible functional relationships between leptin and cerebral activity in humans, simultaneous serum leptin and regional cerebral blood flow (rCBF) measurements were made in 10 obese [BMI 33.5 (29.3–39.1) kg/m²] and 12 normal-weight [BMI 22.2 (20.3–24.6) kg/m²] women during exposure to food. The rCBF measurements were performed by ^99mTc-ethyl-cysteine-dimer single photon emission computed tomography. A strong inverse association was observed between the leptin and rCBF of hypothalamus during the exposure to food in the obese (r = –0.73, p = 0.02, n = 10), but not in the normal-weight subjects (r = 0.22, p = 0.48, n = 12). This suggests that the association of leptin with cerebral activity could be different in obese and normal-weight women; depressed activity of hypothalamic neurones in response to the high peripheral leptin concentration could be postulated to occur in obese women during exposure to food.

Correlation between sex hormones and magnetic resonance imaging lesions in multiple sclerosis.

To determine if sex hormones play a role in the pathogenesis of multiple sclerosis (MS) by correlating serum estradiol and progesterone levels with gadolinium (Gd) enhancing lesions on magnetic resonance imaging (MRI) in MS. Thirty patients with MS were studied with Gd enhanced brain MRI and simultaneous serum estradiol and progesterone levels either during the early follicular, late follicular or luteal phases of their menstrual cycle. Correlation between hormone levels and number of Gd enhancing lesions was determined. Patients with high estradiol and low progesterone levels had a significantly greater number of Gd enhancing lesions than those with low levels of both these hormones. Patients with a high estrogen to progesterone ratio had a significantly greater number of active MRI lesions than those with a low ratio. Estradiol and progesterone may influence disease activity in MS. If further studies confirm these results, it may be possible to develop therapy by altering levels of these hormones.

Evaluation of the gastric mucosa by way of chronologically repeated endoscopies combined with simultaneous serum Helicobacter pylori antibody assay

Evaluation of the gastric mucosa by way of chronologically repeated endoscopies combined with simultaneous serum Helicobacter pylori antibody assay

Acute Hyponatremic Encephalopathy After a Cerebrovascular Accident

A 66-year-old hypertensive male with acute intracerebral hemorrhage developed acute hyponatremic coma 3 days after the addition of enalapril and a combination of amiloride and a thiazide diuretic to his hypotensive regimen. The patient recovered consciousness and serum sodium normalized 2 days after fluid restriction and withdrawal of both medications. Three weeks later, upon inadvertent reinstitution of enalapril and indapamide, severe hyponatremic encephalopathy promptly recurred; recovery was again rapid following fluid restriction and withdrawal of both medications. This temporal relationship establishes the thiazide diuretic or the angiotensin converting enzyme inhibitor or both as the cause of the profound symptomatic hyponatremia in this patient. Results of simultaneous serum and urine osmolality assays on several occasions were consistent with a decrease in free water clearance, a result of either increased antidiuretic hormone (ADH) secretion or potentiation of its peripheral action, and thiazide-induced natriuresis. The use of a thiazide diuretic in the presence of either of these aberrations of ADH homeostasis most likely explains the profound and rapid development of hyponatremia. Drug-induced disturbances in serum osmolality are a potentially reversible cause of deterioration of the mental state in a patient with an acute cerebrovascular accident.

Pharmacokinetics and pharmacodynamics of fluoroquinolones

'Division of Clinical Pharmacology, Department of Medicine, Albany Medical College, Albany, New York, USA; 21NSERM U479, Service d'Hematologie et d'Immunologie Biologiques, CHU Xavier BICHAT, Paris, France; 3Department of Infectious Diseases, Uppsala University Hospital, Uppsala, Sweden; 4Hoechst Marion Roussel Inc, Bridgewater, New Jersey, USA; 5Med Klinik 111, Frankfurt a m Main, Germany; 61nstitute for Biomedical & Pharmaceutical Research, Nurnberg Herodsberg, Germany; 7Hoechst Marion Roussel AG, Clinical Development, Frankfurt a m Main, Germany

Time to Positivity of a Rapid Bedside Assay for Cardiac-Specific Troponin T Predicts Prognosis in Acute Coronary Syndromes: A Thrombolysis in Myocardial Infarction (TIMI) 11A Substudy

Objectives. We sought to determine whether the rapid bedside assay for troponin T identified patients at risk for a more complicated hospital stay and a higher rate of adverse clinical events.Background. In patients with an acute coronary syndrome, the amount of cardiac-specific troponin T released bears a stoichiometric relation to the extent of myocardial damage.Methods. In 597 patients with unstable angina or non–Q wave myocardial infarction participating in the Thrombolysis in Myocardial Infarction (TIMI) 11A substudy, a rapid bedside assay and simultaneous quantitative serum measurement for troponin T were obtained at enrollment.Results. The composite end point of the sum of death, nonfatal myocardial infarction or recurrent ischemia through day 14 occurred in 33.6% of patients with a positive assay compared with only 22.5% of patients with a negative assay (p = 0.01). Those patients in whom the rapid assay became positive in ≤10 min had the highest mortality rate of 4.2% through day 14 compared with 1.1% in those patients who had either a late-appearing positive assay (>10 min) or a negative assay. The duration of hospital stay in the 116 patients (19%) with a positive rapid assay at enrollment was a median of 5 days compared with only 3 days in the 481 patients (81%) with a negative rapid assay at enrollment (p = 0.002).Conclusions. A positive rapid assay for troponin T at presentation identifies those patients at risk for higher rates of adverse clinical events and longer, more complicated hospital stays. Stratification of patients by time to development of a positive rapid assay identifies those patients at highest mortality risk.

Pharmacodynamics and pharmacokinetics of spiramycin and their clinical significance.

The absolute bioavailability of oral spiramycin is generally within the range of 30 to 40%. After a 1 g oral dose, the maximum serum drug concentration was found to be within the range 0.4 to 1.4 mg/L. The tissue distribution of spiramycin is extensive. The volume of distribution is in excess of 300 L, and concentrations achieved in bone, muscle, respiratory tract and saliva exceed those found in serum. The intracellular penetration of spiramycin is also rapid and extensive, with the concentrations in alveolar macrophages 10 to 20 times greater than simultaneous serum concentrations. Spiramycin is less metabolised than some of the other macrolides. The renal excretion of spiramycin is low, with 4 to 20% of the dose being excreted by this route. High concentrations of spiramycin are achieved in bile, which is an important route of elimination. The serum elimination half-life of spiramycin is between 6.2 and 7.7 hours. Of significance to clinicians may be the finding that spiramycin is highly concentrated in the respiratory tract and other tissues and macrophages. The post-antibiotic effect of spiramycin is significant and this effect is more prolonged than that of erythromycin against Staphylococcus aureus. Spiramycin has also been shown to greatly reduce the capacity of strains of Gram-positive cocci to adhere to human buccal cells.