Mobilization of peripheral blood stem cells with docetaxel and cyclophosphamide (CY) in patients with metastatic breast cancer: a randomized trial of 3 vs 4 g/m2 of CY

The purpose of this study was to develop a regimen of docetaxel, cyclophosphamide (CY) and filgrastim for mobilization of peripheral blood stem cells (PBSC) in patients with metastatic breast cancer (n = 66). A phase I trial of CY 2, 3 or 4 g/m2 with docetaxel 100 mg/m2, in consecutive cohorts of four patients each, did not reveal any dose-limiting toxicities and subsequent patients were randomized to receive 3 or 4 g/m2 of CY. The median yield of CD34+ cells from all patients was 11.06x10(6)/kg (range, 0.03-84.77) from a median of two aphereses (range, 1-7); 6.52x10(6) CD34+ cells/kg/apheresis (range, 0.01-52.07). Target CD34+ cell doses > or =2.5 and > or =5.0x10(6)/kg were achieved in 89% and 79%, respectively. There were no statistically significant differences in CD34+ cell yields or target CD34+ cell doses achieved following 3 or 4 g/m2 of CY. Patients with only one prior chemotherapy regimen yielded a median of 12.82x10(6) CD34+ cells/kg/apheresis compared to 5.85 for those receiving > or =2 regimens (P = 0.03). It was concluded that the combination of docetaxel, 100 mg/m2, CY 3 g/m2 without mesna could be administered with acceptable toxicity with collection of adequate quantities of PBSC from the majority of patients.

Site-directed mutations of the FAD-linked glycerophosphate dehydrogenase gene impairs the mitochondrial anchoring of the enzyme in transfected COS-7 cells

COS-7 cells were transfected with the green fluorescent protein (GFP) of Aequorea victoria, human mitochondrial FAD-linked glycerophosphate dehydrogenase (mGDH), a mGDHwt-EGFP construct, or two mutant mGDH-proteins fused with EGFP. The site of mutation was selected to affect cationic amino acids in the peptide signal sequence currently believed to play a key role in the subcellular distribution of mitochondrial proteins. All proteins were suitably expressed in the COS-7 cells. However, an increase in mGDH enzymatic activity above the control value in non-transfected COS-7 cell homogenates was only observed in cells transfected with mGDH, indicating that the catalytic activity of mGDH was masked in fused proteins. Confocal microscopy documented that, in the cells transfected with the mGDHwt-EGFP construct, the fusion protein was located exclusively in mitochondria, this contrasting with the nuclear labelling of cells expressing the green fluorescent protein alone. The mitochondrial anchoring of the mutated mGDH fused protein was altered, this alteration being most obvious in the mGDH313233-EGFP mutant. These findings raise the idea that a conformation change of the mGDH protein, as resulting from either an inherited or acquired alteration of its amino acid sequence, may affect its subcellular distribution and, hence, modify its immunogenic potential.

[Carpal tunnel syndrome: clinical and neurophysiological correlation: review of 100 cases]

INTRODUCTION

The diagnosis of carpal tunnel syndrome (CTS) continues to be neurophysiologically and clinically controversial. This study attempts to find the correlation between the subjective symptomatology and the neurophysiological affectation, establishing a diagnostic guide for the family doctor in order to recognize early CTS for referral to the specialist doctor.

PATIENTS AND METHODS

After a sample of 100 cases with clinical suspicion of CTS, a clinical evaluation was made with the symptoms (paresthesias, pain, loss of strength), signs (Tinel, Phalen), and the neurophysiological evaluation with electroneurography (ENG) of the median and cubital nerve (sensory velocity (SV), motor distal latency (MDL)), and electromyography (EMG) of tenar eminence muscles. With this data an epidemiological study was made with correlation between the clinical and neurophysiological parameters.

RESULTS

The patients with pain, loss of strength and Tinel's sign had significant alteration of the parameters of ENG and EMG. Tinel's sign had a sensitivity (SE) = 30.1% and a specificity (SP) = 73% for MDL, a SE = 32.5% and a SP = 88.2% for SV. Phalen's sign had a SE = 22.2% and a SP = 94.6% for MDL, a SE = 18.1% and a SP = 94.1% for SV.

CONCLUSIONS

The guide to recognize clinically the patients which must be studied neurophysiologically that have a high probability to suffer CTS is: diagnosis for motor alteration, pain (SE = 79%), loss of strength (SP = 86%) and Phalen's sign (SP = 94.6%). Sensory alteration: paresthesias (SE = 97%), Tinel's sign (SP = 88.2%) and Phalen's sign (SP = 94.1%).

Reduction of islet amylin expression and basal secretion by adenovirus-mediated delivery of amylin antisense cDNA

Reduction of amylin content and secretion in rat islets was attempted by transduction with an adenovirus bearing a 0.2-kb fragment of rat amylin cDNA inserted in the antisense orientation (AdCMV-alpha amylin). Exposure of islets to AdCMV-alpha amylin at a multiplicity of infection (moi) of 200 (1.2 x 10(7) pfu/ml) reduced amylin mRNA levels by 37 +/- 5% (p < 0.005), whereas infection with an adenovirus expressing the reporter gene of beta-galactosidase (AdCMV-lacz) did not modify amylin expression. Transduction with the antisense construct was specifically associated with the decrease (30 +/- 6%; p < 0.001) in the amylin content. Insulin content was unaltered in AdCMV-alpha amylin islets compared to AdCMV-lacz-transduced or untransduced cells. Basal amylin secretion (2.8 mM glucose) was 36 +/- 3% (p < 0.005) lower in AdCMV-alpha amylin islets than in untransduced or AdCMV-lacz-transduced islets. In contrast, no difference in amylin secretion in response to high glucose concentrations (16.7 mM) was detected in AdCMV-alpha amylin-transduced islets. Thus, a reduction of amylin content and basal secretion in islet cells can be achieved by the adenovirus-mediated expression of antisense RNA.

Presence of the 918 mutation in the RET proto-oncogene in a Mexican patient with multiple endocrine neoplasia type 2B

The dominantly inherited Multiple Endocrine Neoplasia cancer syndrome type 2B (MEN2B) is characterized by the presence of medullary thyroid carcinoma (MTC), phaechromocytoma (PHAEO), mucosal neuromas, ganglioneuromas of the intestinal tract, skeletal and ophthalmic abnormalities. MEN2B has been associated with a specific point mutation in the tyrosine kinase domain of the RET proto-oncogene (918RET mutation). We investigated a Mexican patient MEN2B for the presence of the 918RET mutation using the polymerase chain reaction followed by restriction endonuclease digestion. We have detected this mutation in DNA from the patient's MTC, PHAEO, and peripheral blood cells, but not in DNA from the patient's mother, suggesting that this mutation arose de novo. Our results are in agreement with the suggestion that the 918RET mutation is present in a vast majority of MEN2B cases around the world.

Nucleotide sequence of cDNA fragments coding for the FAD-,glycerophosphate- and calcium-binding domains of human islet mitochondrial glycerophosphate dehydrogenase

The cDNA fragments coding for the FAD-, glycerophosphate- and calcium-binding domains of mitochondrial glycerophosphate dehydrogenase (mGDH) were synthetized using RNA extracted from freshly isolated pancreatic islets of a normal subject and two-non-insulin-dependent diabetic patients. Single strand conformation polymorphism analysis of the PCR products yielded the same mobility as control cDNA probes. Likewise, the nucleotide sequence and corresponding amino acid sequence were identical to the normal gene bank sequence. These findings argue against the presence, in pancreatic islets, of an mGDH isoform distinct from that previously characterized in extrapancreatic organs.

Determination of residues of the beta-agonist clenbuterol in liver of medicated farm animals by gas chromatography-mass spectrometry using diphasic dialysis as an extraction procedure

A method has been developed for the rapid confirmation of clenbuterol in cow liver using gas chromatography coupled with detection by mass spectrometry of the trimethylsilyl derivatives of clenbuterol. The technique used for the extraction was diphasic dialysis. It was observed that the best suitable solution to homogenize the liver the barium hydroxide-barium chloride buffer, the optimal extraction solvent was tert.-butylmethyl ether at an extraction temperature of 37 degrees C, and stirring should be applied at 150 rpm for 4 h. This extraction method improves clenbuterol recovery up to values of 99.3%. With the use of the barium buffer, derivatization is performed more efficiently and the detection and quantification limits can be decreased to values close to 250 ppt and 500 ppt, respectively.

Long-term prognosis for atypical and malignant meningiomas: a study of 71 surgical cases

To contribute to a better understanding of the prognostic differences between atypical and malignant meningiomas as defined by the World Health Organization (WHO) and the influence of the grade of initial surgical excision on postoperative course, 42 cases of atypical and 29 of malignant meningioma were studied, along with long-term follow up. The two groups were compared with respect to long-term survival, recurrence-free survival, and median time to recurrence. The prognostic significance of the Simpson grade of surgical resection and tumor location was also considered. Survival at 5 and 10 years was recorded in 95% and 79%, respectively, of patients with atypical meningioma and in 64.3% and 34.5% of patients with malignant meningioma (p = 0.001). Recurrence-free survival and median time to recurrence were also significantly longer in patients with atypical than in those with malignant meningiomas: 11.9 versus 2 years (p = 0.001) and 5 versus 2 years (p < 0.0041), respectively. Six (26%) of the 23 recurring atypical meningiomas became malignant. Simpson Grade I resection and location in the cerebral convexity, which were closely related, were found to be associated with a significantly better clinical course in the entire series (p < or = 0.0016). Patients with atypical meningiomas fared better than those with malignant meningiomas after incomplete surgical excision (Simpson Grades II-III), but the difference was not statistically significant. Multivariate analysis using the Cox model indicated that radical extirpation (Simpson Grade I vs. II-III) and histological findings (atypical meningioma vs. malignant meningioma) were significantly related to prolonged survival (p < 0.0003 and p < 0.0388, respectively). In conclusion, the current study shows that for most patients with atypical meningioma the prognosis was less severe than for those with malignant meningioma, but the risk of a downhill course resulting from malignancy after incomplete resection and recurrence was not negligible (26%). In addition, the WHO classification was found to be inadequate for a minority of the atypical meningioma cases, which currently have the same unfavorable course as cases of malignant meningioma. The results also indicate that objective Simpson Grade I extirpation of convexity meningiomas can be successful despite histological findings of malignancy.

Long-term prognosis for atypical and malignant meningiomas: a study of 71 surgical cases

To contribute to a better understanding of the prognostic differences between atypical and malignant meningiomas as defined by the World Health Organization (WHO) and the influence of the grade of initial surgical excision on postoperative course, 42 cases of atypical and 29 of malignant meningioma were studied, along with long-term follow up. The two groups were compared with respect to long-term survival, recurrence-free survival, and median time to recurrence. The prognostic significance of the Simpson grade of surgical resection and tumor location was also considered. Survival at 5 and 10 years was recorded in 95% and 79%, respectively, of patients with atypical meningioma and in 64.3% and 34.5% of patients with malignant meningioma (p = 0.001). Recurrence-free survival and median time to recurrence were also significantly longer in patients with atypical than in those with malignant meningiomas: 11.9 versus 2 years (p = 0.001) and 5 versus 2 years (p < 0.0041), respectively. Six (26%) of the 23 recurring atypical meningiomas became malignant. Simpson Grade I resection and location in the cerebral convexity, which were closely related, were found to be associated with a significantly better clinical course in the entire series (p ¾ 0.0016). Patients with atypical meningiomas fared better than those with malignant meningiomas after incomplete surgical excision (Simpson Grades II-III), but the difference was not statistically significant. Multivariate analysis using the Cox model indicated that radical extirpation (Simpson Grade I vs. II-III) and histological findings (atypical meningioma vs. malignant meningioma) were significantly related to prolonged survival (p < 0.0003 and p < 0.0388, respectively). In conclusion, the current study shows that for most patients with atypical meningioma the prognosis was less severe than for those with malignant meningioma, but the risk of a downhill course resulting from malignancy after incomplete resection and recurrence was not negligible (26%). In addition, the WHO classification was found to be inadequate for a minority of the atypical meningioma cases, which currently have the same unfavorable course as cases of malignant meningioma. The results also indicate that objective Simpson Grade I extirpation of convexity meningiomas can be successful despite histological findings of malignancy.

Mutation in the calcium-binding domain of the mitochondrial glycerophosphate dehydrogenase gene in a family of diabetic subjects

The Ca(2+)-sensitive and mitochondrial enzyme FAD-linked glycerophosphate dehydrogenase (m-GDH) represents an essential component of the pancreatic B-cell glucose-sensing device. This report deals with the first identified case of mutation in the calcium-binding domain of the m-GDH gene in a patient with type-2 diabetes and his glucose-intolerant half sister. Single strand conformation polymorphism analysis indeed revealed an abnormal mobility of the 32P-labelled polymerase chain reaction product in these two subjects. The corresponding base pair mutations and amino acid changes were documented. In the diabetic proband, the relative extent of the Ca(2+)-induced activation of m-GDH in CD3+ T-lymphocytes was lower than in his brother with a normal m-GDH gene sequence.

[Homograft replacement of aortic valve and ascending aorta]

From May 1990 through December 1994, integral valved aortic homografts were implanted for replacement of the aortic valve and of part or the whole of the ascending aorta in 24 patients with a mean age of 45.5 years (17-66 years). Ten patients (41.7%) had infective endocarditis of the aortic valve (4 of the native valve and 6 prosthetic). Seven of these had root abscesses (70%), one with a fistula to the right atrium, resulting in a variable degree of discontinuity between the left ventricle and the aorta. Twelve patients (50%) had ascending aortic aneurysms and the remaining two (8.3%) had aortic dissection. Three patients (12.5%) also had mitral pathology, one had triple vessel coronary disease, one had aortic coarctation and another one had a sub-aortic membrane. Two thirds of the patients were in NYHA class III/IV and 10 (41.7%) had moderate or severe left ventricular dysfunction. A modified Bentall technique utilising fresh aortic homografts was used in all patients. The homografts were harvested aseptically from donors with a mean age of 30 years (16-54 years) and preserved at 4 degrees C for a period of 1-43 days (median-13 days). Six patients (25%) had associated surgery: mitral valve replacement; mitral valvuloplasty with a ring; closure of aortic- atrial fistula, resection of sub-aortic membrane; triple coronary artery bypass; and mitral and tricuspid annuloplasty and closure of ASD (one patient each). Postoperatively three patients (12.5%) required reexploration for excessive blood drainage in the first hours and one patient with complete A-V block required a pacemaker (4.2%). Hospital mortality was 4.2% (one patient). At the time of discharge, no patient had significant Doppler or echocardiographic aortic gradient or regurgitation. All patients were followed for a mean period of 31 months (7-62 months). One patient died of a non cardiac death and the remainder are in NYHA class I without thromboembolic or haemorrhagic accidents and with echocardiographic findings similar to those observed at discharge. These results suggest that aortic homografts constitute an effective and safe method of reestablishing the continuity between left ventricle and aorta, especially in the presence of an infective process with root abscesses.

Clinical algorithm for treatment of Plasmodium falciparum malaria in children

BACKGROUND

Identification of children who need antimalarial treatment is difficult in settings where confirmatory laboratory testing is not available, as in much of sub-Saharan Africa. The current national policy in Malawi is to treat all children with fever, usually defined as the mother's report of fever in the child, for presumed malaria. To assess this policy and to find out whether a better clinical case definition could be devised, we studied acutely ill children presenting to two hospital outpatient departments in Malawi.

METHODS

The parent or guardian of each enrolled child (n = 1124) was asked a standard series of questions about the symptoms and duration of the child's illness. Each child was examined, axillary and rectal temperatures and blood haemoglobin concentrations were measured, and a giemsastained thick smear was examined for malaria parasites. Logistic regression procedures were used to identify clinical predictors of parasitaemia.

FINDINGS

High temperature (37.7 degrees C or above), nailbed pallor, enlarged spleen, and being seen at one of the clinics rather than the other were associated with an increased risk of malaria parasitaemia in univariate analyses. A revised malaria case definition of rectal temperature of 37.7 degrees C or higher, splenomegaly, or nailbed pallor was 85% sensitive in identifying parasitaemic children and 41% specific; the corresponding sensitivity and specificity for the nationally recommended definition that equates mother's history of fever with malaria were 93% and 21%. The revised case definition had 89% sensitivity in identifying parasitaemic children with haemoglobin concentration below 80 g/L and 89% sensitivity in identifying children with parasite density greater than 10,000/microL, characteristics that indicate a clear need for antimalarial treatment.

INTERPRETATION

These results suggest that better clinical definitions are feasible, that splenomegaly and pallor are helpful in identifying children with malaria, and that much overtreatment of children without parasitaemia could be avoided.

Validity of mother's history regarding antimalarial drug use in Malawian children under five years old

History obtained from parents and carers is an important, and often the only, source of information for health workers treating children for malaria, but its validity has not been well evaluated. At 2 hospitals in Malawi, we obtained malaria treatment histories from mothers of 973 ill children reported to have had fever as part of the illness. Urine samples were collected from 755 of the 973 children (78%). Of the 755, 457 (61%) were reported to have received some kind of treatment. Among those who reportedly received treatment, 79 (17%) were said to have received chloroquine and 23 (5%) a sulphonamide-containing medicine; however, when urine specimens were tested for antimalarial drugs, chloroquine was found in 182 specimens (40%) and a sulphonamide in 148 (32%). Among urine specimens collected from 291 children who were reported to have received no treatment (no report was recorded for 7 children), chloroquine was detected in 56 (19%) and a sulphonamide in 44 (15%). Although not statistically significant, mothers often reported a child as not having received an antimalarial drug if the child was younger than 12 months or had been sick for more than 3 d. The mothers' information regarding home treatment of fever in children was highly inaccurate. Malaria treatment histories, whether collected at health facilities or in surveys of knowledge, attitudes, and practices, must be interpreted with caution.

[Fine needle aspiration biopsy of thyroid nodules. Analysis of results obtained using a new method with histological examination of the sample]

Fine needle aspiration biopsy (FNAB) is the most useful preoperative work up method for patients with nodular goiter. We analyze 173 patients that underwent FNAB and were subsequently operated. The sample with FNAB was processed both for cytological and histological study, using methods developed at the hospital. The preoperative diagnosis reached was compared with that obtained with the surgical piece. Results showed that the histological analysis of the FNAB sample improved the sensitivity of the method, when compared with the cytological study, from 68.5% to 87.8% (p < 0.035) without modifying specificity (100% for both methods). It is concluded that FNAB with histological study of the sample has a high diagnostic yield and is exempt of complications.

A double-blind, placebo controlled study of Alpare mite D. pteronyssinus immunotherapy in asthmatic patients

Results from one immunotherapy study can be difficult to extrapolate when physicians use products or dose schedules that differ from the ones used in that particular study. The purpose of this study was to determine if an alum absorbed Alpare D. pteronyssinus extract administered in a maintenance dose of 10,000-12,500 BU's could be shown to improve symptoms in asthmatic patients allergic to D. pteronyssinus. Previous studies using higher doses of extracts suggested efficacy but frequent side effects were noted. A double blind placebo controlled study was performed which included 24 active and 25 placebo patients. We measured skin reactivity, methacholine challenge changes, symptoms by visual analog score, specific IgE levels, and end of study assessment. The results showed significantly greater improvement in actively treated patients versus those given placebo in specific IgE levels, symptoms by visual analog score, and end of study status. We saw no significant differences in skin reactivity, methacholine challenge, or diary medication scores. In addition, no difference in side effects was noted between the two groups. We conclude that the dose administered in this study was safe and well tolerated. Some clinical improvement did seem to occur but the study suggests that higher doses may be indicted in certain patients.

Spinal tumors and subarachnoid hemorrhage: pathogenetic and diagnostic aspects in 5 cases

The authors report 5 cases of spinal tumor associated with subarachnoid hemorrhage. Histologically, the tumor was an ependymoma in 2 cases, a neurinoma in 2 cases and a hemangioblastoma in 1 case. The pathogenetic and diagnostic characteristics of these 5 cases are analyzed in the light of other published reports.

Using clinical signs to diagnose anaemia in African children

Anaemia is a serious and common problem among young children in sub-Saharan Africa. As a first step towards developing guidelines for its recognition and treatment, we conducted a study to evaluate the ability of health workers to use clinical findings to identify children with anaemia. Health care workers examined a total of 1104 children under 5 years of age at two hospital-based outpatient clinics in rural Malawi. Blood samples were taken to determine haemoglobin concentrations. Pallor of the conjunctiva, tongue, palm or nail beds was 66% sensitive and 68% specific in distinguishing children with moderate a anaemia (haemoglobin concentration, 5-8 g/dl) and 93% sensitive and 57% specific in distinguishing those with severe anaemia (haemoglobin concentration, < 5 g/dl). Even without laboratory support, which is often unavailable in rural Africa, clinical findings can identify the majority of children with anaemia.

[Papillary cystic tumor of the pancreas: an infrequent carcinoma of good prognosis]

Papillary cystic tumor of the pancreas is a rare low grade carcinoma, with only 130 cases reported in the English literature. We report a 22 years old female presenting with a palpable mass and abdominal pain. Abdominal ultrasound and CAT scan showed a solid-cystic lesion in the head of the pancreas. The patient was subjected to a partial pancreatoduodenectomy and the histological study of the surgical specimen disclosed a papillary cystic carcinoma. Post op course was uneventful and the patient is well at 8 months follow up.

Epileptic seizures in intracerebral hemorrhage: a clinical and prognostic study of 55 cases

Fifty-five cases of epileptic siezures associated with spontaneous intracerebral hemorrhage are reported. Seizures appeared as the first symptom in 23 patients, early (within two weeks after HI) in 18 and late (later than 2 weeks after HI) in 14. From the analysis of the observed cases we noticed that: 1) partial seizures were most frequent type (63%). These appeared mainly in cases with lobar hemorrhage above all; 2) development chronic epilepsy occurred frequently in the case of patients affected by late seizures. We compare our data with those reported in literature in order to highlight main factors which affect the onset and development of seizures associated with spontaneous intracerebral haemorrhage.

Plasma exchange in systemic lupus erythematosus. Experience in thirty-seven patients

Thirty-seven (37) SLE patients submitted to therapeutic plasmapheresis were examined. The results were good in the active stage of the disease. Various types of antibody, anti-DNA, anti nucleus, anti-cardiolipine, I.C. (Clq and C3d) were removed. The values of IgG, coagulation factors, creatinine and proteinuria were assessed. Close collaboration with the clinicians is urged, with the aim of applying immunosuppressive therapy immediately after P.E. to consolidate the results obtained.

Angiomatosis at the Saphenofemoral Junction

Objective:

To describe 12 patients with a vascular malformation found at the saphenofemoral junction during dissection of the inguinal region for surgery of varicose veins.

Design:

Retrospective study of cases found during the period from 1986 to 1991.

Setting:

University Hospital of the Military School of Medicine, Bogota, Colombia.

Patients:

Twelve patients, 11 unilateral and one bilateral, representing 0.5% of our total experience in surgery of varicose veins in 5 years.

Interventions:

Surgical resection of the angiomatous malformation.

Main outcome measures:

Clinical assessment of patients and histological examination of excised tissue.

Results:

The excised angiomatous tissue was found to contain irregular venous vessels, associated with lymphatic nodular structures and surrounded by adipose tissue. A satisfactory clinical outcome was obtained in patients where the angiomatous tissue could be excised.

Conclusions:

Vascular surgeons treating varicose veins should be aware of the possibility of finding vascular angiomatous malformation of the saphenofemoral junction. Surgical resection of these benign lesions results in a satisfactory clinical outcome.

[Value of bronchoalveolar lavage in the diagnosis of pulmonary involvement in storage diseases]

A 17 years old female with hepatosplenomegaly and pulmonary infiltrates since the age of four is presented. Sea-blue histiocyte disease, a sphingolipidosis, was diagnosed by liver biopsy, bone marrow aspirate and bronchoalveolar lavage. The relevance of bronchoalveolar lavage as a diagnostic method in cases of systemic diseases with pulmonary involvement is emphasized.

Total Bacterial Count in Raw Milk Using the BactoScan 8000

The BactoScan 8000 (Foss Electric) automatically performs a total count of bacteria in raw milk. It was designed for fast, repeatable counting. The apparatus counts the individual bacteria (IBC) instead of colony forming units (CFU). IBC provides more information on the state of milk hygiene than the CFU count. The repeatability, sr, was 0.033 log (IBC/μL), which is equivalent to a coefficient of variation of 7.9% (IBC/μL). The carryover, which is the contamination one sample imposes on the next, was 0.19%. The BactoScan 8000 was calibrated against the reference method of counting colonies on a Petri dish. The correlation coefficient for 429 milk samples was r= 0.88, and the standard deviation of the residuals, syx, was 0.259. The detection limit was 15 CFU/μL. We recommend establishing a system of payment to farmers based on the bacteriological quality of their milk as determined by the BactoScan 8000. Because results are obtained in IBC/μL, analytical differences resulting from conversion to CFU/|iL are eliminated.