Pseudomembranous colitis caused by antibiotic therapy during aorto-iliac surgery

Pseudomembranous colitis is not a rare complication of antibiotic therapy. 2000 surgical procedures with implantation of grafts in the aorto-iliac region were performed from 1974 through 1988; during this period 11 cases of CMP were observed. The Authors report their experience in regard to the various antibiotics administered.     

Magnetic resonance in the staging of multiple myeloma]

The authors retrospectively reviewed the MR examinations of 46 patients with clinical and laboratory findings of monoclonal gammopathies (MG). All cases had been submitted to radiographic examination which had shown skeletal involvement in 22 cases and osteoporosis in 11, with rupture of the vertebral body in 3 patients. Scintigraphy had been performed on all patients and CT on 12; 36 patients were subsequently submitted to follow-up (at 6, 12 and 24 months). MR examinations were performed with dedicated coils and standard sequences for the subjects with skeletal localizations on X-ray images. The extant cases, with no radiographic evidence of skeletal involvement, were submitted to MRI of the spine, skull and pelvis. In agreement with clinical and laboratory findings and with follow-up results (in 36 patients), MRI diagnosed MG with no skeletal involvement in 13 cases, osteoporosis in 8 (with rupture of the vertebral body in 2), asymptomatic non-progressive myeloma in 4, solitary myeloma in 3, and multiple myeloma in 18 cases. The good identification of bone marrow and its multiplanarity make MRI the method of choice in the study of patients with suspected or known gammopathies. If compared with other modalities, MRI is more sensitive and accurate in depicting the tumor, its size and relationship to periskeletal tissues, and its possible multifocality. Moreover, the technique has proven to be a valid tool during the follow-up, showing tumor response to therapy.     

Lumbar disk herniation: MR imaging assessment of natural history in patients treated without surgery.

The aim of this study was to evaluate the evolution of lumbar disk herniation in patients treated without surgery. Sixty-nine patients with a lumbar disk herniation proved at magnetic resonance (MR) imaging underwent a follow-up MR imaging study. The disk herniations evaluated during both MR imaging examinations were measured and classified into four categories according to the change in size that occurred. The patients were also divided into three clinical classes on the basis of the clinical outcome. Sixty-three percent of the patients showed a reduction of disk herniation of more than 30% (48% had a reduction of more than 70%), while only 8% demonstrated worsening of the clinical picture. These findings suggest that lumbar disk herniation may be primarily a medical (nonsurgical) disease and that MR imaging could play an important role in management of and research into the disorder.     

Therapy of refractory/relapsed acute myeloid leukemia and blast crisis of chronic myeloid leukemia with the combination of cytosine arabinoside,tetrahydrouridine, and carboplatin

Summary Eight patients, of whom four had acute myeloid leukemia (AML) and four had chronic myeloid leukemia (CML) blast crisis, were treated with a combination of cytosine arabinoside (ARA-C: 1,600 mg/m² in three patients, 1,200 mg/m² in five patients), tetrahydrouridine (THU: 2,800 mg/m² in two patients, 2,646 mg/m² in one patient, 2,100 mg/m² in five patients), and carboplatin (900 mg/m² in four patients, 720 mg/m² in one patient, 450 mg/m² in three patients). As a result of this treatment, five of the eight patients became aplastic. Two of the four patients with CML blast crisis reverted to the chronic phase and two of the four patients with acute nonlymphocytic leukemia (ANLL) attained a remission (one partial remission and one complete remission). The major toxicities included myelosuppression, unacceptable hepatotoxicity, and diarrhea. Pharmacokinetics studies revealed that the addition of carboplatin did not significantly change the disposition of ARA-C. ARA-C levels were not significantly changed in comparison with those obtained in a prior study of ARA-C with THU (ARA-C plasma levels at 3 h, 2630±1170 ng/ml).Supported by the Don Monti Memorial Research Foundation     

Novel MC1R variants in Ligurian melanoma patients and controls

Several variant forms of the melanocortin-1 receptor gene (MC1R) have been associated with red hair, fair skin and an increased risk for melanoma. Their involvement in melanoma susceptibility is apparently linked both to skin sensitivity and to non-pigmentary pathways. We investigated the frequency of the MC1R variants in the Italian region of Liguria, where the occurrence and penetrance of melanoma are low and primary susceptibility is characterized by prevalence of the CDKN2A c.301G>T [p.G101W] founder mutation. Additionally, we attempted to establish the frequency of the red hair/fair skin phenotype in our region. As predicted by anecdotal evidence, the frequency of red hair/phototype I was very low (0.7%). Screening of 17 red-haired individuals and their red-haired relatives, 207 controls and 214 melanoma patients unselected for hair color but all of Ligurian descent, led to the detection of 8 novel substitutions (c.133T>C [p.F45L], c.248C>T [p.S83L], c.332C>T [p. A111V], c.479G>A [p.R160Q], c.637C>T [p.R213W], c.793G>A [p. V265I], c.923C>T [p. T308M], c.943T>C [p.C315R]), 1 novel deletion (c.520_523delGTC [p.V174del]) and 3 novel synonymous variants (c.366G>C [p. V122V], c.684G>A [p. Q228Q], c.726C>T [p.T241T]). Preliminary genotype/phenotype correlation seems to indicate that other genes involved in the regulation of human pigmentation may mask the recessive action of high-penetrance MC1R alleles, thus determining the low frequency of at-risk phototypes and of incidence and/or penetrance of melanoma in Liguria.     

Biological activities of monoclonal antibodies to Mycoplasma pneumoniae membrane glycolipids.

A purified preparation of membranes was obtained by using a unique method of treating Mycoplasma pneumoniae with the ATPase inhibitor, diethylstilbestrol. This method was shown to yield highly purified membranes with little or no cytoplasmic contamination. These membranes were used to immunize mice for subsequent productions of monoclonal antibodies (MAbs). Hybridoma culture supernatants were screened by enzyme-linked immunosorbent assay with whole-cell M. pneumoniae and lipid extract antigens. Four stable MAbs were obtained and characterized. MAb CP3-46F5 reacted with a protein of a molecular weight of approximately 52,000 as determined by Western blot (immunoblot). MAbs CP3-50C2, CP3-53C5, and CP3-53C8 did not react with any antigens on Western blots but did bind to at least 10 distinct glycolipid bands as determined by orcinol staining on thin-layer chromatograms of M. pneumoniae lipid extracts. The MAbs did not react with similarly prepared lipid extracts from Mycoplasma genitalium, Mycoplasma neurolyticum, and Mycoplasma gallisepticum. These MAbs did not inhibit M. pneumoniae metabolism or attachment to WiDr cell cultures. The anti-glycolipid MAbs recognize determinants specific to M. pneumoniae, unlike polyclonal hyperimmune sera against M. pneumoniae, which cross-react with lipid extracts of M. genitalium.     

Mycoplasma pneumoniae attachment: competitive inhibition by mycoplasmal binding component and by sialic acid-containing glycoconjugates.

Attachment of Mycoplasma pneumoniae to human WiDr cell culture monolayers was examined by using radiolabeled M. pneumoniae. The amount of attachment was proportional to the density of the WiDr cells and to the concentration of M. pneumoniae in the assay. Saturation of the monolayers was achieved with 40 micrograms of virulent strain M129 per assay, whereas binding of avirulent strain B176 was 70% less than that of strain M129. A competitive attachment inhibition assay was used to measure specific binding component activity. Attachment was inhibited when WiDr cells were pretreated with unlabeled virulent strain M129, whereas avirulent noncytadsorbing strain B176 did not inhibit attachment as well as the virulent strain. A protein-rich extract prepared from virulent, cytadsorbing strains of M. pneumoniae also inhibited attachment. The amount of inhibition was dependent on the amount of extract used, and units for binding component activity in the extract were calculated from the competitive attachment inhibition assays. The competitive attachment inhibition assay was also used to investigate the nature of the receptor site on the WiDr cells. Attachment was inhibited when the radiolabeled M. pneumoniae suspensions were pretreated with human sialoglycoproteins, such as orosomucoid and ceruloplasmin, and bovine gangliosides. These findings support the present concept that the mammalian receptor site for M. pneumoniae is a sialic acid-containing glycoprotein.     

Anti-mitochondrial flavoprotein autoantibodies of patients with myocarditis and dilated cardiomyopathy (anti-M7): interaction with flavin-carrying proteins, effect of vitamin B2 and epitope mapping

Vitamin B2 and flavin cofactors are transported tightly bound to immunoglobulin in human serum. We reasoned that anti-mitochondrial flavoprotein autoantibodies (alpha Fp-AB) present in the serum of patients with myocarditis and cardiomyopathy of unknown aetiology may form immunoglobulin aggregates with these serum proteins. However, immunodiffusion and Western blot assays demonstrated that the flavin-carrying proteins were not recognized by alpha Fp-AB. Apparently the flavin moiety in the native protein conformation was inaccessible to alpha Fp-AB. This conclusion was supported by the absence of an immunoreaction between the riboflavin-binding protein from egg white and alpha FP-AB. Intravenous application of vitamin B2 to rabbits immunized with 6-hydroxy-D-nicotine oxidase, a bacterial protein carrying covalently attached FAD, did not neutralize alpha Fp-AB which had been raised in the serum of the animals. FAD-carrying peptides generated from 6-hydroxy-D-nicotine oxidase by trypsin and chymotrypsin treatment were not recognized by the alpha Fp-AB, but those generated by endopeptidase Lys were. This demonstrates that the epitope recognized by alpha Fp-AB comprises, besides the flavin moiety, protein secondary structure elements.     

Obesity and Circulating Levels of Vitamin D before and after Weight Loss Induced by a Very Low-Calorie Ketogenic Diet

Background: Vitamin D plays a pivotal role in calcium and phosphorus metabolism, also influencing bone tissue. Several studies have reported that vitamin D blood levels were significantly lower in people with obesity, probably due to its uptake by the adipose tissue. Clinical studies that investigated the changes of circulating levels of vitamin D following weight loss reported controversial data. A very low-calorie ketogenic diet is acknowledged as a reliable treatment to achieve a rapid weight loss. Therefore, we investigated the effect of weight loss, consequent to a very low-calorie ketogenic diet, on vitamin D blood concentrations. Methods: A cohort of 31 people with obesity underwent a very low-calorie ketogenic diet for 10–12 weeks. The serum concentrations of vitamin D, parathormone, calcium and phosphorous were measured before and after weight loss; they were compared to a control group of 20 non-obese, non-diabetic, age- and gender-matched persons. Results: Patients with obesity had a higher habitual intake of vitamin D than the control group (p < 0.05). However, the vitamin D blood levels of the obese group were significantly lower than those of the control group (p < 0.005) and they increased after weight loss (p < 0.001). At baseline, vitamin D blood concentrations of the persons with obesity were significantly correlated with both fat mass–kg (r = −0.40; p < 0.05) and body mass index (r = −0.47; p < 0.01). Following very low-calorie ketogenic diet, the change in vitamin D serum concentrations was correlated only with the change in fat mass–kg (r = −0.43; p < 0.01). Conclusion: This study confirmed that patients with obesity have lower vitamin D levels that normalize after significant weight loss, supporting the hypothesis that vitamin D is stored in the adipose tissue and released following weight loss.