Minimal Iliac Bone Harvesting in Sinus Lift Surgery

For sinus grafting, the authors propose a minimal posterior iliac bone harvesting, with local anesthesia. Autogenous bone grafting continues to be considered the gold standard for sinus grafting. The classic harvesting sites are calvarial, anterior iliac, and tibial, and harvesting is usually practiced under general anesthesia. We performed this technique in 7 patients under local anesthesia. In the posterior iliac crest, with a specific trocar for bone puncture biopsy, bone was harvested. We performed 1 cm longer for 5-mm diameter of bone. Three bone biopsies were harvested on each side. The harvested cancellous bone (5 cm3) was mixed with triphosphocalcic (TCP) material (2 cm3), and blood (1 cm3). A classic sinus lift was realized. After 6 months, the success rate of bone grafting was 100%. Each of the 7 patients could be implanted by an average of 4 dental implants by superior maxillary. For sinus lift, this simple posterior iliac-bone biopsy harvesting under local anesthesia is very comfortable for the patient and also safe. It provides enough marrow bone to be mixed with TCP for a sinus lift.

[Total nasal reconstruction with a titanium miniplate as structural support]

INTRODUCTION

Total nasal reconstructions using bone graft, as structural support is the gold standard. We retrospectively studied an alternative technique relying on a titanium miniplate as a structural support.

PATIENTS AND METHODS

Five patients underwent total nasal reconstruction, using a 1mm titanium miniplate fixed to the frontal bone and to the anterior maxilla. The miniplate was covered by a fascia lata graft in three cases. The functional and aesthetic results were evaluated on a scale from 0 (disappointing results) to 3 (excellent results) by the patient and by the surgeon, at 1 month and at 3 years after the total nasal reconstruction.

RESULTS

The functional results were assessed on average at 2.2/3 at 1 month, and 2.4/3 at 3 years postoperatively. The aesthetic results are estimated at 2 (patient) and 1.8 (medical team) at 1 month and at 2.6 (patient) and 2.2 (medical team) at 3 years. There were no major complications. The minor complications were exposure of the two miniplates, which had not been covered with fascia lata. These complications were resolved by local surgery.

DISCUSSION

The functional and aesthetic results of total nasal reconstruction relying on a titanium miniplate were similar to those obtained with a bone graft. This technique is simple, there is no need for an osseous donor site, it is stable at long-term, and its cost is moderate.

[PEEK customized implant for skull esthetic reconstruction]

INTRODUCTION

Craniotomies provide unsightly sequels. Conservative methods for the removed bone, autologous graft, or use of surgical cement do not always allow restoring cranial symmetry. A customized PolyEtherEtherKetone (PEEK) implant may then be used. This implant is made from 3D CT reconstruction. The PEEK material is biocompatible, conformable, strong enough to protect the brain.

TECHNICAL NOTE

The authors report a case of aesthetic reconstruction of a large cranial defect using a customized PEEK implant. Balloon scalp expansion was performed before implant placement.

DISCUSSION

The aesthetic results are satisfactory, the postoperative short and simple. PEEK is a good alternative to titanium implants for customized implants; it is easier to use and lighter. This customized implant is well suited to correct unsightly sequels of craniotomy.

Impact of immigration on tuberculosis in a low-incidence area of Italy: a molecular epidemiological approach

The effects that immigration might have on the epidemiology of tuberculosis (TB) in a low-incidence area of Italy was investigated by determining, in autochthonous and immigrant TB patients, the molecular characteristics of the Mycobacterium tuberculosis complex (MTBC) isolates, which may provide information on their phylogeographical origin. A total of 1080 MTBC strains, collected during a 4- year period in Tuscany from 614 Italian-born and 466 foreign-born patients, were genotyped by spoligotyping and assigned to the different phylogeographical lineages that constitute the MTBC. The autochthonous Euro-American phylogeographical lineage, which includes the spoligotype families T, Haarlem, Latin American–Mediterranean (LAM), S and X, was highly prevalent among Italian-born patients, with a total of 477 cases (77.7%), and foreign-born TB patients, with a total of 270 cases (57.9%); 24 Italian-born (3.9%) and 141 foreign- born (30.3%) TB cases were due to MTBC genotypic families associated with distant geographical areas, i.e. East African–Indian (EAI), Beijing, Central Asian (CAS), and Mycobacterium africanum. Strains of Mycobacterium bovis and strains of undefined genotype, which are all considered together, as it is not possible to assign a specific geographical origin, accounted for 113 (18.4%) Italian cases and 55 (11.8%) foreign-born cases. A total of 79 Italian TB cases (12.9%) have been attributed to transmission from immigrants to the local population. No significant contribution to drug resistance appeared to be associated with imported MTBC strains. It is concluded that, at present, the overall impact of imported TB on public health in the low-incidence study area is relatively modest and of the same order as in other western countries.

[Orbital fractures in children]

The aim of this article is to review data concerning paediatric orbital fractures. These fractures exhibit strong specificities because they occur in a growing face. Due to the craniofacial growing pattern and the peumatization of paranasal sinuses, there are differences in the anatomical location of orbital fracture with the age: before the age of seven they are mostly orbital roof and after seven they involve the orbital floor. The clinical diagnosis is confirmed with a computed tomography scan (CT scan), gold standard for the imaging in the orbital fractures. The magnetic resonance imaging (MRI) offers a better soft-tissue depiction and is useful when clinical data are not consistent with CT scan findings. The orbital fractures in children are rarely operated. In emergency the main surgical indications are the trap-door fracture involving the ocular muscles and the compressive haematomas. We hypothesize that the periosteum more likely than the bony structure is involved in the responsible trap-door fractures: the thickness and the elasticity of the periosteum leads to reposition the floor or the medial wall of the orbit to its initial position.

[Keloids: pathogenic and therapeutic advances]

Keloids are benign fibroproliferative tumors but often cause serious cosmetic problems. Considered as scars results from abnormal wound healing, keloids appear at preferential sometimes highly unsightly locations (e.g. the ear) and often involve predisposed individuals with genetically pigmented skin. The underlying pathophysiological mechanisms are unclear and no consensus on treatment.

[Sialendoscopy of the salivary glands]

INTRODUCTION

Sialoendoscopy is a simple efficient mode of treatment for major salivary gland sialoliths and strictures.

METHODS

Sialendoscopy procedure requires specific devices, diagnostic and therapeutic sialendocopes, minigrasping forceps, wire baskets, lasers, balloons and stents. The sialendoscopy procedure is divided in three steps: the duct introduction step (through the papilla or through the duct wall); the diagnostic step (from main duct to third or fourth salivary division branches) and the therapeutic step (stone removal with a Dormia basket or miniforceps and stenosis balloon dilatation). The feasibility of stone removal depends on the size, the position, the mobility and the shape of the stone. The only contraindication is acute sialadenitis.

DISCUSSION

Sialendoscopy complications are minor. Its success rate for stone removal is greater than 90%, and it has dramatically reduced the rate of sialadenectomy (to less than 5%).

Mutations responsible for Mycobacterium tuberculosis isoniazid resistance in Italy

SETTING

The incidence of tuberculosis (TB) and drug resistance in Italy is low compared to other countries. Mutations in several genomic regions of Mycobacterium tuberculosis are involved in the occurrence of isoniazid (INH) resistance.

OBJECTIVE

To investigate the mutations responsible for INH resistance among Italian isolates of M. tuberculosis, to assess the feasibility of predicting drug resistance using a genetic approach.

DESIGN

The mutations responsible for INH resistance were looked for in selected regions of genes katG, kasA and ndh and in the promoter regions of inhA and ahpC by nucleotide sequencing, and the results were compared with data reported in other studies.

RESULTS

Prevalent INH resistance mutations were found at codon 315 of the katG gene and at position -15 of the inhA regulatory region (respectively 37.8% and 20.0% of isolates). The prevalence of mutations at position -24 of inhA, in ahpC, and in kasA ranged from 2.2% to 4.4%. No mutations were found in 35.6% of the isolates.

CONCLUSION

The identification of INH resistance by genetic analysis of the selected regions may be inappropriate in areas with a low prevalence of TB, such as Italy, as the genetic mechanisms of resistance remain unidentified for approximately one third of the isolates.

Requirement of gene fadD33 for the growth of Mycobacterium tuberculosis in a hepatocyte cell line

Gene fadD33 of Mycobacterium tuberculosis, one of the 36 homologues of gene fadD of Escherichia coli identified in the M. tuberculosis genome, predictively encodes an acyl-CoA synthase, an enzyme involved in fatty acids metabolism. The gene is underexpressed in the attenuated strain M. tuberculosis H37Ra relative to virulent H37Rv and plays a role in M. tuberculosis virulence in BALB/c mice by supporting mycobacterial replication in the liver. In the present paper, we investigated the role of fadD33 expression in bacterial growth within the hepatocyte cell line HepG2, as well as in human monocyte-derived THP-1 cells and peripheral blood mononuclear cells. M. tuberculosis H37Rv proved able to grow within HepG2 cells, while the intracellular replication of M. tuberculosis H37Ra was markedly impaired; complementation of strain H37Ra with gene fadD33 restored its replication to the levels of H37Rv. Moreover, disruption of gene fadD33 by allelic exchange mutagenesis reduced the intracellular growth of M. tuberculosis H37Rv, and complementation of the fadD33-disrupted mutant with gene fadD33 restored bacterial replication. Conversely, fadD33 expression proved unable to influence M. tuberculosis growth in human phagocytes, as fadD33-disrupted M. tuberculosis H37Rv mutant, as well as fadD33-complemented M. tuberculosis H37Ra, grew within THP-1 cells and peripheral monocytes basically at the same rates as parent H37Rv and H37Ra strains. The results of these experiments indicate that gene fadD33 expression confers growth advantage to M. tuberculosis in immortalized hepatocytes, but not in macrophages, thus emphasizing the importance of fadD33 in liver-specific replication of M. tuberculosis.

Genes of Mycobacterium tuberculosis H37Rv downregulated in the attenuated strain H37Ra are restricted to M. tuberculosis complex species

By comparing gene expression of virulent Mycobacterium tuberculosis H37Rv and attenuated strain H37Ra, we previously detected six genes that appear to be markedly downregulated in the attenuated strain compared with the virulent one. Three of these genes, i.e. Rv1345, Rv2770c, and Rv0288, code for proteins that can be predictively associated to immunological or pathogenetic aspects of M. tuberculosis infection; the other genes, i.e. Rv2336, Rv1320c, and Rv2819c, code for proteins with unknown functions (Rindi et al., 1999). In this paper we searched for the above mentioned genes in Pvu II-digested genomic DNA of a number of mycobacterial species by southern blot analysis employing PCR-generated probes in high-stringency conditions. Hybridization signals were only found in species belonging to the M. tuberculosis complex, i.e., M. tuberculosis, M. bovis, including the BCG strain, and M. microti, but not in other mycobacterial species, including M. avium, M. intracellulare, M. malmoense, M. xenopi, M. kansasii, M. simiae, M. marinum, M. scrofulaceum, M. gordonae, M. fortuitum, and M. smegmantis. These results indicate that genes Rv1345, Rv2770c, Rv0288, Rv2336, Rv1320c, and Rv2819c are associated with the most virulent mycobacteria and further support their potential role in M. tuberculosis virulence.

IS6110-based restriction fragment length polymorphism (RFLP) analysis of Mycobacterium tuberculosis H37Rv and H37Ra

IS6110-based restriction fragment length polymorphism (RFLP) analysis of Mycobacterium tuberculosis H37Rv and its avirulent mutant H37Ra was performed by a number of restriction enzymes, including Nru I, EcoN I, Pst I, and Pvu II. No differences were found in the IS 6110-fingerprints of the study strains by Nru I. One differential IS6110-positive restriction fragment was detected by EcoN I in strain H37Ra, while analysis by Pst I revealed that two fragments of the strain H37Rv were replaced by four novel IS6110-positive fragments in the strain H37Ra. By using Pvu II, a restriction enzyme that cleaves IS 6110 once, and by probing for an IS6110 specific target sequence located to the right of the Pvu II site, we found that the strains H37Rv and H37Ra share 13 IS6110-positive restriction fragments and that one IS6110-positive restriction fragment of H37Rv is replaced by four novel fragments in H37Ra; by probing for an IS6110-specific target sequence to the left of the Pvu II site, 13 shared restriction fragments and 2 differential bands in strain H37Ra were detected. These findings demonstrate that novel insertions of the IS6110 element exist in the avirulent strain H37Ra and raise the question of the role, if any, of IS6110-insertional mutagenesis in the establishment of the avirulent M. tuberculosis H37Ra phenotype.

Search for genes potentially involved in Mycobacterium tuberculosis virulence by mRNA differential display

An mRNA differential display (DD) assay was developed to compare gene expression between Mycobacterium tuberculosis H37Rv and its avirulent mutant H37Ra. The DD protocol made use of an oligo(dT) to prime reverse-transcriptase (RT)-dependent transcription of poly-A tailed mRNAs and a PCR amplification of the RT products by using ten 12-base arbitrary primers in all their pair combinations. This analysis yielded 745 and 708 bands, including 52 and 15 differentially generated bands, in the strains H37Rv and H37Ra, respectively. Six cDNAs that appeared to be expressed in H37Rv, but not in H37Ra, were reamplified and cloned and at least 10 inserts were sequenced for each cloned cDNA. After resolving discrepant results, 6 inserts were found highly homologous to M. tuberculosis H37Rv genes. Three of these, i.e., genes Rv2770c, Rv1345, and Rv0288, coding respectively for a member of the PPE protein family, a probable polyketide synthase, and a member of the protein family containing ESAT-6, have been predictively associated to immunological or pathogenetic aspects of M. tuberculosis infection; the other genes, i.e., Rv2336, Rv1320c, and Rv2819c, code for proteins with unknown functions. These results show that mRNA DD methodology can represent a potential tool for investigation of M. tuberculosis gene expression.

Typing of human Mycobacterium avium isolates in Italy by IS1245-based restriction fragment length polymorphism analysis

All but 2 of 63 Mycobacterium avium isolates from distinct geographic areas of Italy exhibited markedly polymorphic, multibanded IS1245 restriction fragment length polymorphism (RFLP) patterns; 2 isolates showed the low-number banding pattern typical of bird isolates. By computer analysis, 41 distinct IS1245 patterns and 10 clusters of essentially identical strains were detected; 40% of the 63 isolates showed genetic relatedness, suggesting the existence of a predominant AIDS-associated IS1245 RFLP pattern.

Oligo(dT)-primed synthesis of cDNA by reverse transcriptase in mycobacteria

The possibility that mRNA from Mycobacterium tuberculosis and M. bovis BCG may present polyadenylation at the 3' end was investigated. The total RNA, extracted from the bacterial cells and treated with DNase, was used as substrate for reverse transcriptase (RT)-dependent cDNA synthesis. The RT reaction was primed with oligo(dT) and with downstream specific primers for the genes of the antigens 65 KDa and 85-C. PCR probing of the reaction products for cDNAs of the two mycobacterial genes yielded the expected 225 and 307 bp bands when RT synthesis was primed by oligo(dT) and by downstream specific primers. Reaction products from oligo(dT)-primed RT of RNase-treated RNA and untranscribed RNA, probed by PCR, failed to generate the 225 and 307 bp specific bands. These findings support the existence of polyadenylated tracts in mRNA of mycobacteria that can be targeted by oligo(dT) primers to initiate RT-dependent cDNA synthesis. This may result in an advance in the study of gene expression in these and possibly other bacteria.

Comparison of three restriction endonucleases in IS1245-based RFLP typing of Mycobacterium avium

IS1245-based restriction fragment length polymorphism (RFLP) analysis has been proposed recently for molecular typing of Mycobacterium avium isolates. As there is no standardised method with respect to the optimal restriction enzyme, three restriction endonucleases were tested for analysis of 17 human isolates. The restriction endonucleases, selected on the basis of the physical maps of IS1245 and of the highly homologous IS1311, were BsaAI, that cleaves IS1245, PvuII, that cleaves IS1311, and NruI, that cleaves both IS1245 and IS1311. All the restriction endonucleases yielded polymorphic and complex RFLP patterns. However, BsaAI- and NruI-generated bands were more evenly distributed and easier to detect than PvuII-generated bands, most of which clustered in a narrow zone of the fingerprint. In some cases, DNA digestion with BsaAI or NruI yielded probe-specific restriction fragments of molecular size lower than expected. Moreover, digestion with NruI, which was expected to generate the highest numbers of bands in all the isolates, yielded fewer bands than were obtained with BsaAI or PvuII in 14 and 5 isolates, respectively. These findings might suggest the existence of unidentified IS1245-related insertion element(s) in M. avium isolates. Computer analysis of the IS1245-based RFLP patterns of M. avium isolates showed that the restriction endonucleases were capable, although with minor differences, of defining distinct banding patterns and clusters of identical or highly related isolates, thus confirming IS1245-based RFLP analysis as a useful technique for epidemiological studies.

DNA restriction fragments length polymorphism of Mycobacterium tuberculosis isolates in Pisa, Italy

A total of 60 Mycobacterium tuberculosis strains isolated in the area of Pisa, Italy, over a period from April 1993 to December 1995, were analyzed for the IS6110-based restriction fragments length polymorphism (RFLP). Isolates were found to show a great heterogeneity and only few isolates shared identical DNA banding patterns. In particular, 55 distinct IS6110 patterns were found (average number of isolates per pattern: 1.09) and only 9 strains (15%) occurred in 4 clusters of 2-3 identical clones. Computer analysis of genetic similarities among the strains revealed a family of 17 isolates including the clustered clones implicated in recently acquired infections. No correlation was found between the RFLP DNA patterns of the isolates and drug susceptibility. Of the 5 isolates from immigrants only one showed abnormal DNA fingerprinting. Our data indicate that the patterns of M. tuberculosis isolates in Pisa area are comparable to those of countries with low-prevalence TB and that a low level of TB transmission occurs in this area.

Evidence of nosocomial transmission of tuberculosis among AIDS patients by DNA fingerprinting

DNA restriction fragment length polymorphism (RFLP) analysis was performed on Mycobacterium tuberculosis isolates from patients in the human immunodeficiency virus (HIV) Unit of a community hospital. It was found that M. tuberculosis isolates from two patients with AIDS shared an identical RFLP pattern. Such a fingerprint was not found in M. tuberculosis isolates from any of 40 HIV-negative patients hospitalized in different Units over the same period, assumed as representative of the strains present in the community, thus ruling out that the isolates from the two AIDS patients might match because only a few strains were present in the community. Clinical records of the two AIDS patients showed an 8-day concomitant hospitalization period in the same ward during which one of the two patients showed active tuberculosis; the second patient developed active tuberculosis less than two months later. These findings strongly support the possibility of nosocomial transmission of tuberculosis.