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PubMed2002

The general mixing of addicts and needles in a variable-infectivity needle-sharing environment.

In this paper we develop and analyse a model for the spread of HIV/AIDS amongst a population of injecting drug users. The model we discuss focuses on the transmission of HIV through the sharing of contaminated drug injection equipment and in particular we examine the mixing of addicts and needles when the AIDS incubation period is divided into three distinct infectious stages. The impact of this assumption is to greatly increase the complexity of the HIV transmission mechanism. We begin the paper with a brief literature review followed by the derivation of a model which incorporates three classes of infectious addicts and three classes of infectious needles and where a general probability structure is used to represent the interaction of addicts and needles of varying levels of infectivity. We find that if the basic reproductive number is less than or equal to unity then there exists a globally stable disease free equilibrium. The model possesses an endemic equilibrium solution if the basic reproductive number exceeds unity. We then conduct a brief simulation study of our model. We find that the spread of disease is heavily influenced by the way addicts and needles of different levels of infectivity interact.

Computer Simulation↗
PubMed2006

Successful recovery of esophageal patency in 2 patients with complete obstruction by using combined antegrade retrograde dilation procedure, needle knife, and EUS needle.

BACKGROUND: Esophageal occlusion is typically caused by cancer or postradiation changes; it is difficult to treat, with poor surgical outcomes. The combined antegrade retrograde dilation (CARD) method has been used to endoscopically restore the esophageal lumen after complete occlusion by cancer or postradiation changes, with good preliminary results. Reproducing this technique and improving its speed and convenience would be advances in treating this difficult clinical problem. OBJECTIVE: A demonstration of 2 alternative endoscopic techniques for treating complete esophageal obstructions. DESIGN: The CARD method was performed in 2 patients with unresectable cancer and complete esophageal occlusion. In the first patient, a needle knife was used to cut through the obstruction, instead of removing it piecemeal with biopsy forceps before over-the-wire dilation. In the second patient, an EUS needle was used to cross a particularly long obstruction, which allowed subsequent dilation and recanalization. SETTING: A tertiary referral center. PATIENTS: Two patients with complete esophageal obstruction secondary to head and neck cancer, with associated radiation therapy. RESULTS: In both cases, this method resulted in successful recanalization of the occluded lumen in a relatively short amount of time, without complications. LIMITATIONS: The small number of patients in this series. CONCLUSIONS: The CARD needle-knife method may be a safe, effective, and efficient approach to complete esophageal occlusion. In addition, the CARD-EUS needle method may be an preferable technique to cross long obstructions quickly; however, more experience will be required.

Aged↗
PubMed1996

Aspiration needle biopsy refines preoperative diagnosis of thyroid nodules defined at fine needle aspiration as microfollicular nodule.

The aim of this paper was to verify the hypothesis that large needle biopsy performed preoperatively can refine preoperative fine needle aspiration (FNA) cytological diagnoses of microfollicular nodules. Since 1980 we have been using FNA and aspiration needle biopsy (ANB) (18 or 16 gauge needles) to select for surgery all euthyroid patients with palpable thyroid nodules referred to our department. From 1980 to 1994, 6,124 patients (12% male, 88% female) with thyroid nodules (71% single, 29% multiple) were examined by FNA; 29% of these patients were also examined preoperatively by ANB histology. Of all the nodule patients examined, 371 received a preoperative FNA diagnosis of microfollicular nodule. Two hundred and fifty-four of these nodules (68%) were also examined preoperatively by ANB. Unsatisfactory ANB specimens constituted 17% of cases; pure microfollicular structure was confirmed by ANB in 36% of the nodules; ANB showed the remaining 47% to contain a macrofollicular component, thus suggesting a benign hyperplastic lesion. Twelve nodules which were found to be microfollicular at FNA cytology and micro-macrofollicular at ANB were excised and were subsequently determined as benign at definitive postoperative histology. These data indicate the utility of ANB in refining the preoperative FNA diagnosis of microfollicular nodule and in preoperatively identifying benign hyperplastic mixed micro-macrofollicular lesions which can be followed by observation.

Adult↗
PubMed2001

US-guided fine needle aspiration versus coarse needle biopsy of thyroid nodules.

OBJECTIVE: The aim of this study was retrospectively to evaluate ultrasound (US) guided fine-needle aspiration (FNA), in combination with US-guided coarse-needle biopsies, (CNB) from solitary or dominant thyroid nodules routinely performed during a 2 year period. METHODS: Seventy seven patients were biopsied using US-guided FNA and CNB. FNA was performed using a 21-Gauge needle and CNB using a 18-Gauge single action spring-activated needle biopsy system. The biopsies were performed with local anaesthesia. The Department of Pathology routinely examined the biopsy specimens. The retrieval rate in obtaining material for diagnostic evaluation was FNA (97%), CNB (88%), FNA and CNB (100%). RESULTS: In all, 41 of the 77 patients underwent neck-surgery. The surgical specimens were used to determine the results of diagnosing neoplasia. The accuracy, sensitivity and specificity for FNA were 80, 83, and 77%. For CNB 86, 78, and 94%. For both FNA and CNB 80, 89 and 73%. The diagnostic value of the two methods showed no significant difference (P < 0.05). CNB revealed contrary to FNA, however, one additional cancer. Also a higher number of false positive findings was noticed using FNA. No serious complications were registered. Adequate biopsies were obtained in all the patients using the combination of US-guided FNA and CNB. No patient underwent rebiopsy. CONCLUSIONS: The study demonstrated that neither US-guided CNB nor the combination of US-guided FNA and CNB were superior to US-guided FNA. US-guided CNB is only recommended in few selected patients.

Adult↗
PubMed2004

Detection of recurrent papillary thyroid carcinoma by thyroglobulin assessment in the needle washout after fine-needle aspiration of suspicious lymph nodes.

To evaluate an efficient method of surveillance of low-risk patients with thyroid cancer, ultrasound was performed on 74 postoperative patients being followed for stage I and II papillary carcinoma. All patients were clinically free of cancer 1-43 years after a total thyroidectomy, and were screened with ultrasound and thyroglobulin (Tg) measurement while taking thyroid hormone suppression. Ultrasound revealed findings suspicious of recurrent disease in the lymph nodes of the neck in 21 patients. An ultrasound-guided fine-needle aspiration (FNA) to obtain material for cytology and Tg analysis was done on these 21 patients, 7 of whom tested positive for Tg in their needle washout. Only 3 of the 7 had detectable Tg in their serum, and only 5 of the 7 had positive cytology. Ultrasound (with FNA-Tg analysis of needle washout of suspicious lymph nodes) is proposed as an effective and efficient method of surveillance in these low-risk patients. Presence of Tg in the needle washout proved to be more sensitive than cytology in diagnosing cancer in the lymph nodes and was not affected by positive anti-Tg antibodies in the serum.

Adolescent↗
PubMed2006

The impact of assessing specimen adequacy and number of needle passes for fine-needle aspiration biopsy of thyroid nodules.

Fine-needle aspiration biopsy (FNAB) of thyroid nodules is a safe, cost-effective procedure but the rates of inadequate cytology specimens range from approximately 1% to 15%. This study tests the hypothesis that ultrasonographically (US) guided FNAB and onsite assessment of cytology improves the adequacy rate of FNAB. A retrospective analysis was performed on 693 thyroid FNAB specimens obtained with and without ultrasound guidance and with or without onsite cytology assessment. Overall, 29 specimens (4%) were inadequate for diagnosis. Among 163 cystic nodules and 530 solid nodules, inadequacy rates were 15% (n = 24) and 1% (n = 5) respectively (p = 0.0001). An onsite assessment of cytology for adequacy was done in 550 cases (83%), which was more accurately performed by a cytopathologist (97%) than a cytotechnologist (93%, p = 0.015). With US-guided FNAB, 3% of the cytology specimens were inadequate, compared to a 7% rate when US was not done (p = 0.003). The mean number of needle punctures necessary for an adequate specimen was 3.8 +/- 0.06 (median, 3.0; range, 1-11), which was different among various types of doctors, ranging from 3.2 +/- 0.07 to 5.4 +/- 0.12 (p = 0.001 analysis of variance [ANOVA]). The fewest number of needle passes to achieve an adequate specimen were required by university endocrinologists and pathologists working together (average, 3.2 +/- 0.07; median, 3.0; range, 1-11). Sample inadequacy rate varied significantly among physician groups, ranging from 3% to 18% (p = 0.0001 ANOVA). Stepwise regression analysis showed that onsite assessment of cytology, US-guided FNAB (p = 0.16), and cystic nature of the nodule (p < 0.0001 for all) correlated with adequacy of the specimen. We conclude that US-guided FNAB with onsite evaluation of cytology specimens substantially increases the adequacy of cytology specimens and decreases the number of required needle passes, which ultimately reduces patient discomfort and diagnostic errors, thus raising the question as to whether this should eventually become the standard of care. We believe this is a goal that training programs should strive to achieve.

Adolescent↗
PubMed1977

Peripheral nerve injury due to injection needles used for regional anesthesia. An experimental study of the acute effects of needle point trauma.

Nerve injury can arise as a complication peripheral nerve block anesthesia. Of the various factors involved, the trauma caused by the injection needle may be of significance. In this experimental study the frequency of fascicular injury was investigated immediately after needling isolated rabbit sciatic nerve preparations, and after intraneural injection with the nerve in situ. Two different injection needles were used, one with a bevel angle of 14 degrees and the other with a 45 degrees bevel angle. Fascicular injury was indicated by a fluorescence microscopy technique, tracing locally applied Evans Blue Albumin, The results show that a 45 degrees-beveled needle less frequently produces fascicular damage and should therefore be recommended for use in clinical anesthesia. It is also concluded that paresthesiae, when necessary, should be elicited gently, and that intraneural injections should be avoided.

Anesthesia, Conduction↗
PubMedDate not supplied

Radiofrequency ablation using perfused needle electrodes - study of intermittent and continuous triple needle application ex vivo.

To increase necrotic zones, bovine livers were treated by means of three parallel-oriented radiofrequency ablation (RFA) needles spaced at 3 cm using a puncture guide. The triple application was varied as a continuous and intermittent energy application compared to a single needle applicator. In all three study arms the applied energy (60 W) and the perfusion rate (240 ml/h) were kept constant. After treatment the smallest necrosis diameter was determined. In addition, temperature and the device's power output were monitored. Our study shows that synchronous use of three RFA application needles achieves significantly larger necrosis zones ex vivo than does single needle application. Intermittent energy application heats up the necrosis faster and more evenly with highest average temperature than continuous energy application.

Animals↗
PubMed1999

Preoperative diagnosis of medullary thyroid carcinoma by RT-PCR using RNA extracted from leftover cells within a needle used for fine needle aspiration biopsy.

Fine needle aspiration Biopsy (FNAB) is commonly used to diagnose thyroid tumors. In some clinical situations, however, accurate diagnosis requires a more objective method than cytological examination alone. Medullary thyroid carcinomas (MTC) derive from C cells in the thyroid and express some specific messenger RNAs (mRNA), such as those transcribed from the RET proto-oncogene, the calcitonin gene, and the gene for carcinoembryonic antigen (CEA), which usually do not exist in normal thyroid follicular cells or thyroid tumors of follicular epithelial descent. Recently, we established a new method for the molecular diagnosis of thyroid tumors without additional invasion to the patient by extracting RNA for RT-PCR from the leftover cells inside the needles used for fine needle aspiration biopsy (Aspiration Biopsy-Reverse Transcription-Polymerase Chain Reaction, ABRP). By applying the ABRP method to the detection of RET, calcitonin, and CEA mRNAs, an accurate molecular-based diagnosis for MTC maybe established as an adjunct to cytological diagnosis. In this study, 35 aspirates were obtained at the time of surgery from thyroid tumors, including 11 MTCs. The expression of these mRNAs in the leftover cells inside the needles used for the aspiration was then examined. Transcripts from all three genes were detected in the samples from all 11 MTCs, but none of these mRNAs were detected in the other tumors or normal thyroid tissues. Furthermore, MTC was preoperatively diagnosed in three patients by ABRP detection of these mRNAs, and these diagnoses were confirmed by subsequent cytological and histopathological analyses. Thus RT-PCR detection of RET, calcitonin, and CEA mRNAs in FNABs may be an efficient molecular adjunct for diagnosing MTC.

Adult↗
PubMed1992

Conventional 15 G needle technique for renal biopsy compared with ultrasound-guided spring-loaded 18 G needle biopsy.

Two techniques for percutaneous renal biopsy were retrospectively reviewed to assess their relative safety and efficacy. Ultrasound localization of the kidney by a radiologists, with subsequent biopsy performed by a renal physician using a hand-held 15 G cutting needle (Tru-Cut), was compared with biopsy performed by a radiologist using an 18 G cutting needle with a spring-loaded biopsy device (Biopty) and real-time ultrasound guidance. The smaller needle with real-time ultrasound is more reliable at retrieving an adequate specimen for histological examination (93%) than the "conventional" technique (79%). Fewer complications occurred in the Biopty group although the difference did not reach statistical significance. The average length of stay in hospital was significantly shorter for elective biopsies with the Biopty device (1.80 compared with 2.93 nights, p less than 0.01). We recommend the use of the Biopty device with an 18 G needle and real-time ultrasound guidance as the method of choice for percutaneous renal biopsy.

Adolescent↗
PubMed2004

Diagnostic value of transbronchial needle aspiration by Wang 22-gauge cytology needle in intrathoracic lymphadenopathy.

OBJECTIVES: The aim of this study was to investigate the diagnostic value of transbronchial needle aspiration (TBNA) performed with a Wang 22-gauge cytology needle in patients with mediastinal and/or hilar adenopathy. DESIGN: Cross-sectional study. SETTING: Tertiary care training hospital. PATIENTS: TBNA procedures were performed using a flexible bronchoscope and a 22-gauge Wang needle in 60 consecutive patients (36 women and 24 men; mean age, 39 +/- 16 years [+/- SD]) who had mediastinal or hilar adenopathy identified on CT of the chest. RESULTS: Adequate lymph node sampling was obtained from 59 of 60 patients (98%). We were able to make a diagnosis in 45 of 60 patients (75%). TBNA was the only tool of diagnosis in 30 of the 60 patients (50%). Diagnoses included tuberculosis (n = 21), sarcoidosis (n = 21), carcinoma (n = 15), and lymphoma (n = 3). Adequate material was obtained from 20 of 21 patients with tuberculosis. The diagnosis made by TBNA was tuberculosis in 13 of 20 cases (65%). In 12 patients, diagnosis of tuberculosis was made cytologically; for the remaining 1 patient, mycobacterial culture was used. TBNA was the only diagnostic tool utilized in 8 of 20 patients with tuberculosis (40%). Diagnostic material was obtained from 16 of 21 patients with sarcoidosis (76%). In sarcoidosis, TBNA provided the only diagnostic specimen in 13 of 21 patients (62%). In all 15 patients with carcinoma (100%), diagnostic materials were obtained. Adequate but nondiagnostic samples were obtained from two patients with lymphoma, and one patient had lymphoma successfully diagnosed with TBNA. No complications were seen except minimal bleeding. CONCLUSION: TBNA performed with a Wang 22-gauge cytology needle is an effective and safe way of obtaining cytologic specimens from intrathoracic lymph nodes and can rapidly provide diagnosis, both in malignant and benign mediastinal diseases. Hopefully, this technique will reduce further need for more invasive surgical procedures.

Adult↗
PubMed1991

Evaluating needle exchange: do distributed needles come back?

We employed capture-recapture methods as a strategy for evaluating needle exchange. Needles distributed by the exchange at two time periods were marked with color coded bands indicating the date and site of distribution. Half of the marked needles (2,068/4,239) returned within two weeks of distribution, and 61 percent (2,593/4,239) returned during the study period. The rate of return for stationary exchange sites (63 percent) was greater than that for roving/mobile sites (51 percent; chi 2 = 28.6, p less than .001). Of all needles returned, 87 percent (2,248/2,593) returned to the site of original distribution.

Acquired Immunodeficiency Syndrome↗
PubMed2006

The efficacy of single-needle versus double-needle hemodialysis in chronic renal failure.

OBJECTIVE: The purpose of the present study was to assess single-needle dialysis adequacy and other parameters of dialysis efficiency, such as recirculation, hematocrit, calcium and phosphorus level. The complications and adverse events were also evaluated. Time to achieve maximal adequacy of dialysis were compared between 4, 4.5, and 5.0 hours of dialysis session. DESIGN: Prospective, cross-over trial. SETTING: Renal Unit, Department of Medicine, Bangkok Metropolitan Administration Medical College and Vajira Hospital. MATERIAL AND METHOD: Seven stable chronic renal failure patients who regularly used standard hemodialysis (HD) technique with double-needle (DN) were recorded for baseline data including Kt/V percent recirculation, calcium and phosphorus level, hematocrit, and LDH level. Subsequently, all the patients were placed on single-needle dialysis (SN) for 3 consecutive duration, 4 hours, 4.5 hours and 5.0 hours respectively for 3 weeks in each period. The same parameters were recorded at the end of each period. RESULTS: Prior to the single-needle phase, the adequacy of dialysis in DN dialysis were within the acceptable range. After switching to SN mode, the Kt/V did not change significantly from the baseline value. However, subgroup analysis in twice weekly dialysis revealed some degree of reduction in Kt/V value albeit not significant. In the thrice weekly group, the Kt/V did not differ from the baseline value and achieved the target level according to the DOQI guideline. The other parameters such as hematocrit, calcium, phosphorus and LDH were not different from the DN group. SN dialysis did not cause more recirculation than the DN group and both were less than 10 percent. There were no other major complications during the SN phase. The outcome of the fistulas were excellent. CONCLUSION: The SN dialysis has the same efficacy as the conventional DN technique in terms of Kt/V and other parameters such as calcium, phosphorus and LDH values. Both DN and SN caused less than 10% recirculation. There were no reports of adverse events during the treatment period. The double-pump system therefore could be suitable for routine thrice weekly HD in a selected group of patients.

Adult↗
PubMed1991

Fine needle aspiration cytology, imprint cytology and tru-cut needle biopsy in breast lumps: a comparative evaluation.

Fine needle aspiration cytology, imprint cytology and tru-cut needle biopsy were performed in 86 patients with breast lump and the results of these techniques were finally compared with the incisional or excisional biopsy in all the patients. Fine needle aspiration cytology had the sensitivity of 96.8% and specificity of 100%, the imprint cytology had the sensitivity of 98.4% and specificity of 100%. While the tru-cut needle biopsy had the sensitivity and specificity of 100% though in this technique 15 of 86 (17.4%) specimens were rejected as insufficient for any diagnosis.

Biopsy, Needle↗
PubMed1990

Metallurgically bonded needle holder jaws. A technique to enhance needle holding security without sutural damage.

A new needle holder jaw face has been specifically designed and developed to increase needle holding security without sutural damage. Tungsten carbide particles have been metallurgically bonded into the stainless steel jaw to create a fine granular surface. This bonded jaw enhances needle holding security by limiting either twisting or rotation of the clamped needle. In addition, compression of the monofilament synthetic sutures by the bonded jaws does not reduce suture breaking strength.

Equipment Design↗
PubMed1988

[Ultrasound controlled fine needle cytology and fine needle histology in circumscribed pancreatic processes].

Using a biopsy transducer 171 fine-needle punctures of focal pancreatic processes were done in 158 patients. The final diagnosis was made in the first group by surgical operation or autopsy, in the second by the further clinical course. The sensitivity of the cytological examination alone was 78% in the first group and 90% in the second. The histological examination alone had a sensitivity of 79% to 100%. Combining both ways of examination according to defined criteria the sensitivity in the first group was 84% and in the second 100%. The specificity was 100% for both. The complications were 2.9%. Of these 5 cases one pancreatitis had to be operated. There were no lethal complications. To optimize the sensitivity and specificity of the ultrasound guided fine needle puncture technique we want to recommend the following points: A biopsy transducer or puncture-aid must be available. The fine needle technique only should be done under the prerequisite of a high frequency of punctures and a high constancy in the relation between puncturer and pathologist. To receive representative material it can be necessary to make several needle passes during one session. Material for cytological und histological examination should always be taken simultaneously.

Adult↗
PubMed1988

Needle-tract seeding after percutaneous fine-needle biopsy of pancreatic carcinoma. Case report.

Needle-tract seeding is a rare complication following percutaneous fine-needle biopsy of intra-abdominal tumours and only a few cases have been reported. Two cases of cutaneous implantation of a tumour in the needle-tract after biopsy of pancreatic carcinomas are presented. In experimental studies, seeding of malignant cells in the needle-tracts is common and the discrepancy between experimental and clinical findings is discussed.

Adenocarcinoma↗
PubMedDate not supplied

[Prospective study comparing the results obtained by liver puncture biopsy with Chiba fine needle and Menghini needle in some tumors of the liver].

Seventy-eight consecutive patients (mean age 59 years) have been submitted to concomitant liver biopsy with Menghini and Chiba needles. The same place in the liver was reached by both needles. In 54 cases there was a clinical suspicion of malignancy and in 24 patients biopsy was indicated by other reasons. In 60 cases the biopsies were oriented by laparoscopy. Comparing the results attained by Menghini needle ("gold standard") and the results of the cytologic study of the material obtained with Chiba needle, the last method has proved to be sensible (92.7%), specific (97.3%) and reliable (accuracy = 94.9%).

Adolescent↗