Percutaneous multiple-site parietal pleural biopsy: description and evaluation of a new and safe technique

STUDY OBJECTIVES: (1) To describe a new percutaneous pleural biopsy technique to obtain multiple-site parietal pleural biopsy specimens in patients with pleural effusion (PE), and (2) to evaluate its effectiveness and safety compared to current techniques. DESIGN: Prospective interventional study. SETTING: University teaching hospital. PATIENTS: Consecutively referred for evaluation of exudative PE. INTERVENTION: With the patient in a semirecumbent position, a 9F sheath was inserted by the Seldinger technique into the pleural cavity on the midaxillary line under local anesthesia and fluoroscopic guidance. An 8F bioptome was introduced through it, and biopsy specimens were taken from several sites on the costal and diaphragmatic pleura. After biopsy, PE was completely evacuated, and the sheath was removed. RESULTS: During the 2-year pilot study, we procured, on average, 14 adequate pleural specimens from each of the 28 patients (age range, 15 to 81 years) on the first attempt. Histopathologic examination revealed tuberculous pleuritis (18 patients), metastatic adenocarcinoma (1 patient), and nonspecific pleuritis (9 patients). Postprocedure, 25 patients had rapid symptomatic improvement without recurrence of PE. No major complications occurred during or after the procedure (mean follow-up period, 2 years). CONCLUSIONS: Our new biopsy procedure can be performed easily, safely, and with increased diagnostic sensitivity and patient comfort. Unlike other biopsy techniques, it provides adequate multiple-site pleural biopsy specimens, in all cases, on the first attempt without any morbidity and mortality. It has a therapeutic potential to provide rapid symptomatic relief and treatment by pleurodesis. We recommend this procedure for patients whose conditions remain undiagnosed after undergoing needle biopsy or for those who cannot tolerate it, before considering more aggressive diagnostic interventions. This is the best alternative when thoracoscopy or thoracotomy are not available or when patients are at high risk for complications from them.     

Antibody levels and in vitro lymphoproliferative responses to Streptococcus pyogenes erythrogenic toxin A and mitogen of patients with rheumatic fever.

We investigated the in vitro lymphoproliferative responses to a streptococcal mitogen and erythrogenic toxin A of children with acute rheumatic fever (ARF) and patients with chronic rheumatic heart disease (CRHD). Antibody levels to the streptococcal products were also analyzed in the sera of those with ARF or chronic rheumatic heart disease as well as in the sera of children with streptococcal pharyngitis or poststreptococcal glomerulonephritis. Our results demonstrated that the individuals had depressed lymphoproliferative responses during the active stage of rheumatic fever. The depressed responses were not found either to be induced by time-sensitive mitogen-specific suppressor cells or to be related to a dose-response phenomenon. On the other hand, antibody levels to the extracellular mitogens were significantly elevated in the sera of children with ARF compared with the levels in the rest of the groups. The hyperresponsiveness noted among children with ARF was found to be at a quantitative level and was not due to recognition of more epitopes, as determined by Western blotting (immunoblotting). The profile of immune responsiveness in children with ARF to the streptococcal extracellular mitogens is discussed in relation to the pathogenesis of disease.     

An artificial neural network-based controller for the control of induced paralysis using vecuronium bromide

This study presents an artificial neural network-based controller for regulating the level of induced paralysis during surgery using vecuronium bromide. The controller uses the myogram of a rapid muscle contractions (called twitch) to generate the appropriate infusion rate. The controller is self-adjusting and can accommodate inter- and intrapatient drug response variations. It also withstands changes in the pure time delay and nonlinear pharmacokinetic parameters of the response. Another feature of the controller is that it does not depend ona priori knowledge of the patient response model. Computer simulations using pharmacokinetic and pharmacodynamic models showed negligible steady-state error and maximum percent undershoot averaged to 6.24%. The average infusion rate for 90% paralysis was 1.22 (μg·kg⁻¹·min⁻¹).     

Serial determinations of serum CEA in monitoring management of patients with colorectal carcinoma

Serum concentrations were determined serially in two groups of patients with colorectal carcinoma: in 123 after curative resection and in 34 with residual cancer. Of the first group, in 98 serum CEA fluctuated within the normal range or with a 2-fold larger amplitude evidencing effective surgery because only 9 had recurrence; in 25 serum CEA rose persistently from a postoperative nadir indicating relapse, mostly liver metastases. Of the 34 patients with relapse, 3 had clinically and 7 CEA-directed second-look laparotomy; although 7 had operation with curative intent, only 3 remained disease-free. In the second group, there were 26 patients after palliative surgery and 8 during nonsurgical treatment. Serum CEA fluctuated within the normal range in 2 patients in remission and in 3 with progressive cancer, and rose in parallel to cancer progression in 29. Thus, serum CEA within or slightly above the normal range was 88% predictive that the patient might be free of disease or in remission; whereas elevated or rising level indicated disease progression. Accordance between serum CEA and clinical status occurred in 145 of 157 (92%) patients.     

Fos expression induced by changes in arterial pressure is localized in distinct,longitudinally organized columns of neurons in the rat midbrain periaqueductal gray

The distribution of neurons expressing Fos within the periaqueductal gray (FAG) following pharmacologically induced high or low blood pressure was examined to determine (1) if PAG neurons are responsive to changes in arterial pressure (AP) and (2) the relationship of these cells to the functionally defined hypertensive and hypotensive columns in PAG. Changes in AP differentially induced robust Fos expression in neurons confined to discrete, longitudinally organized columns within PAG. Increased AP produced extensive Fos-like immunoreactivity within the lateral PAG, beginning at the level of the oculomotor nucleus. At the level of the dorsal raphe, Fos expression induced by increased AP shifted dorsally, into the dorsolateral division of PAG; this pattern of Fos labeling was maintained throughout the caudal one-third of PAG. Double-labeling for Fos and nicotinamide adenine dinucleotide phosphate diaphorase confirmed that Fos-positive cells induced by increased AP were located in the dorsolateral division of PAG at these caudal levels. Fos positive cells were codistributed, but not colocalized, with nicotinamide adenine dinucleotide phosphate diaphorase-positive cells. Decreased AP evoked a completely different pattern of Fos expression. Fos-positive cells were predominantly located within the ventrolateral PAG region, extending from the level of the trochlear nucleus through the level of the caudal dorsal raphe. Double-labeling studies for Fos and serotonin indicated that only 1–2 double-labeled cells per section were present. Saline infusion resulted in very few Foslike immunoreactive cells, indicating that volume receptor activation does not account for Fos expression in PAG evoked by changes in AP. These results indicate that (1) substantial numbers of PAG neurons are excited by pharmacologically induced changes in AP and (2) excitatory barosensitive PAG neurons are anatomically segregated based on their responsiveness to a specific directional change in AP. © 1995 Wiley-Liss, Inc.     

An electrophysiological characterization of the projection from the central nucleus of the amygdala to the periaqueductal gray of the rat: the role of opioid receptors

The midbrain periaqueductal gray (PAG) and the central nucleus of the amygdala (CNA) are both known to be involved in fear and anxiety, analgesia, vocalization, cardiovascular and respiratory changes, and freezing. Anatomical studies have shown that a connection between these two regions exists but little is known about the physiology or the neurochemical constituents of this pathway. The goals of this study were to characterize the projection from the CNA to the PAG using electrophysiological techniques and to determine whether μ- and/or δ-opioid receptors, which play a large role in a majority of the functions of the PAG, are involved in this pathway. Of the 38 PAG cells tested with single shock stimulation of the CNA, 44% responded; of those, 46% were excited and 54% were inhibited. The latency to onset of response for the inhibitory cells (12.71 ± 6.61 ms) was shorter than that of the excitatory cells (22.33 ± 4.04 ms). Forty-six percent of the 129 PAG cells tested with train electrical stimulation of the CNA responded; 44% were excited and 56% were inhibited. Chemical stimulation of the CNA (10 mMd,l-homocysteic acid) produced similar results; 48% (62/128) of PAG cells responded; 45% of cells were excited and 55% were inhibited. The baseline firing rate of the inhibitory cells was significantly higher compared to the excitatory cells. Chemical stimulation of the CNA produced an increase in blood pressure in 12 animals, a decrease in two animals, and had no effect on the blood pressure of 68 animals. The blood pressure changes ranged between 8.5 and 26.3 mmHg with a mean of 16.2 ± 2.2 mmHg. The effect of naloxone (given either on site in the PAG or systemically) on the response to CNA stimulation was tested in 21 cells. Twenty-five percent of the excitatory cells (2/8) and 77% (10/13) of the inhibitory cells were blocked by naloxone with the majority of the blocked cells located in the ventrolateral PAG. It is concluded that: (1) Approximately 50% of cells in the lateral and ventrolateral columns of the PAG respond to CNA stimulation; (2) the inhibitory response is mediated by a faster conducting or a more direct pathway than the pathway that mediates the excitatory response; (3) neurons that are inhibited by CNA stimulation have a significantly higher baseline firing rate than neurons that are excited, suggesting that they may be tonically active interneurons; and (4) at least one link in the CNA-PAG pathway utilizes μ- or δ-opioid receptors.     

The first pilot study on characteristics and practice patterns of Kuwaiti breast cancer patients.

Nongenetic breast cancer risk factors have never been evaluated in Kuwait. Accordingly, we aimed at examining these factors as well as the immune profile of the patients. Fifty stage I breast cancer patients and 50 age group-matched normal controls were assessed for the level of their peripheral blood lymphocyte subsets and for risk factors associated with their demographic and reproductive characteristics and with diet. The percentages of CD4+ T lymphocytes, CD4+:CD8+ ratio, and CD19+ B lymphocytes were significantly higher in the patients as compared to controls, while the percentages of CD8+ T lymphocytes and natural killer (CD56+) cells were significantly reduced. Risk factors associated with the disease included higher BMI, lack of regular exercise and physical activity in the past 5 years, early age at menarche, late age at first pregnancy, lack of previous information about breast cancer, hormonal therapy, and presence in Kuwait during the invasion/liberation. Other parameters included significantly more frequent consumption of carbohydrate, sweets, animal fat, and vegetable oil (margarine) and less frequent consumption of fresh vegetables and olive oil. This is the first study to highlight the environmental risk factors associated with breast cancer among the Kuwaiti women. We recommend introducing a nationwide campaign to further investigate these factors and to address them accordingly.     

Comparative study of inactivation of herpes simplex virus types 1 and 2 by commonly used antiseptic agents.

A comparative study of the different reactions of herpes simplex virus types 1 and 2 to Lysol, Listerine, bleach, rubbing alcohol, Alcide disinfectant (Alcide Corp., Westport, Conn.), and various pHs, temperatures, and UV light exposures was performed. Both types of stock virus (titers of approximately 10(6) and 10(5.5) for types 1 and 2, respectively) were inactivated by 0.5% Lysol in 5 min; by Listerine (1:1 mixtures) in 5 min; by 2,000 ppm (2,000 microliters/liter) of bleach in 10 min; by rubbing alcohol (1:1 mixtures) at zero time; by Alcide disinfectant (0.2 ml of virus plus 2.0 ml of Alcide) at zero time; by pHs 3, 5, and 11 in 10 min; and by a temperature of 56 degrees C in 30 min. A germicidal lamp (model G30TB; General Electric Co., Schenectady, N.Y.) (30 W) at a distance of 48 cm failed to completely inactivate the two types in 15 min. Type 1 showed slightly more resistance to Listerine and bleach and significantly more resistance to heat; moreover, pH 9 did not affect the infectivity of either type after 10 min.     

Properties of a projection pathway from the medial preoptic nucleus to the midbrain periaqueductal gray of the rat and its role in the regulation of cardiovascular function

In this study we examined (1) the effect of stimulation of the MPO on the firing activity of neurons in the PAG, (2) the role of glutamic acid in this interaction and, (3) whether reversible blockade of neuronal activity in the PAG by lidocaine can alter the effect of stimulation of the MPO on arterial blood pressure. Single pulse stimulation of the MPO produced a biphasic response in232 cells and inhibited332 cells. Train electrical stimulation excited2154 cells and inhibited1254 cells. The latencies to the onset of the excitatory and the inhibitory effects were not different, but the duration of the excitatory effect was slightly longer than that of the inhibitory effect. Chemical stimulation of the MPO excited1797 cells and inhibited1697 cells. The latency to onset of the excitatory response to stimulation of the MPO was longer but the duration was shorter than that of the inhibitory response. In 83% of the animals (2935), stimulation of the MPO produced a decrease in mean arterial pressure (MAP). The duration of the response was 196.9 ± 20.9 s and the average decrease in the MAP was 18.2 ± 1.4 mmHg. Application of KYN blocked the excitatory response to stimulation of the MPO in816 cells and the inhibitory response of310 cells. Injection of lidocaine into the PAG by itself had no effect on the arterial blood pressure. However, in all animals (n = 10) lidocaine totally or significantly reduced the magnitude of the blood pressure change produced by stimulation of the MPO in a reversible manner. These studies electrophysiologically confirm a pathway between the MPO and the PAG that is, in part, under glutamatergic control. In addition, our results demonstrate that stimulation of the MPO produces a distinctive depressor effect that is mediated through the PAG.