The average roughness and fractal dimension of articular cartilage during drying

Cartilage is a unique material in part because of it biphasic properties. The structure of cartilage is a porous matrix of collagen fibers, permeated with synovial fluid which creates a gliding and near frictionless motion in articulating joints. However, during in vitro testing or surgery, there exists potential for cartilage to dehydrate, or dry out. The effects of this drying can influence experimental results. It is likely that drying also changes joint performance in vivo. In in vitro testing of equine cartilage explants exposed to open air, the average roughness of cartilage changes from 1.85 ± 0.78 to 3.66 ± 1.41 µm SD in a 5-h period. Significant changes in roughness in individual samples are seen within 10 min of exposure to open air. However, the multi-scale nature of cartilage, characterized by the fractal dimension, does not significantly change during the same period. The current study attempts to quantify the magnitude of error that is introduced when cartilage is removed from its native environment.

Effects of intravenous lidocaine overdose on cardiac electrical activity and blood pressure in the horse

This study aimed to identify blood serum lidocaine concentrations in the horse which resulted in clinical signs of intoxication, and to document the effects of toxic levels on the cardiovascular and cardiopulmonary systems. Nineteen clinically normal mature horses of mixed breed, age and sex were observed. Lidocaine administration was initiated in each subject with an i.v. loading dose of 1.5 mg/kg bwt and followed by continuous infusion of 0.3 mg/kg bwt/min until clinical signs of intoxication were observed. Intoxication was defined as the development of skeletal muscle tremors. Prior to administration of lidocaine, blood samples for lidocaine analysis, heart rate, mean arterial blood pressure, systolic blood pressure, diastolic blood pressure, respiratory rate and electrocardiographic (ECG) data were collected. After recording baseline data, repeat data were collected at 5 min intervals until signs of intoxication were observed. The range of serum lidocaine concentrations at which the clinical signs of intoxication were observed was 1.85-4.53 microg/ml (mean +/- s.d. 3.24 +/- 0.74 microg/ml). Statistically significant changes in P wave duration, P-R interval, R-R interval and Q-T interval were observed in comparison to control values, as a result of lidocaine administration. These changes in ECG values did not fall outside published normal values and were not clinically significant. Heart rate, blood pressures and respiratory rates were unchanged from control values. This study establishes toxic serum lidocaine levels in the horse, and demonstrates that there were no clinically significant cardiovascular effects with serum lidocaine concentrations less than those required to produce signs of toxicity.

Oral treatment with a nutraceutical (Cosequin) for ameliorating signs of navicular syndrome in horses

Fourteen horses with a progressive forelimb lameness of 3 to 12 months' duration, diagnosed as navicular syndrome, were selected from clinical cases admitted to Auburn University Equine Hospital for evaluation of the efficacy of an orally administered nutraceutical (Cosequin, Nutramax Laboratories, Inc., Edgewood, MD) for ameliorating clinical signs associated with naturally occurring navicular syndrome. Horses were randomly allocated to treatment with the nutraceutical or a placebo. Treatment was five scoops (16.5 g) of powder twice daily in the feed. The test group (n = 8) received a patented nutraceutical consisting of 9 g of FCHG49 (a highly purified glucosamine HCl), 3 g of TRH122 (a specific purified low-molecular-weight sodium chondroitin sulfate), and 600 mg of manganese ascorbate. The placebo group (n = 6) received an indistinguishable oral powder containing only excipients. Owners and the investigator were unaware of group assignments. The same investigator assessed lameness and overall clinical condition at enrollment and after 4 and 8 weeks of treatment. Lameness was assessed by an algofunctional lameness index, comprising a combined sum score of standing posture, hoof tester examination, and lameness scores at various levels of work. Overall clinical efficacy was rated on a visual analogue scale. Owners assessed lameness via a preassigned questionnaire, incorporating an algofunctional lameness index and overall clinical condition at weekly intervals. Radiographic examinations of the navicular bones were performed at enrollment and after 8 weeks of treatment. The median algofunctional lameness index and overall clinical condition scores assigned the investigator were significantly improved (P = .05) for horses treated with the nutraceutical compared with placebo-treated horses. The degree of improvement in algofunctional lameness index assigned by owners after 8 weeks was also significant (P = .045) between the treatment groups. Radiographic scores after treatment were not significantly different between the groups (P > .05).

Pseudallescheria boydii infection of the nasal cavity of a horse

An 18-year-old 454-kg (1,000-lb) American Quarter Horse gelding was evaluated because of chronic intermittent malodorous right-sided nasal discharge. Endoscopy revealed a mycotic plaque in the nasal cavity adjacent to the nasomaxillary opening of the right caudal maxillary sinus. The nasomaxillary opening appeared to be larger than normal. Fungal culture of specimens of the mycotic plaque yielded Pseudallescheria boydii. The horse was treated with 2% miconazole intranasally, sodium iodide i.v., and potassium iodide p.o. Thirty and 60 days after treatment was initiated, the nasal cavity was found to be free of infection.

Ligature slippage during standing laparoscopic ovariectomy in a mare

Suture ligature failure is a potential complication during laparoscopic ovariectomy techniques utilizing ligatures as a means of hemostasis. This complication in the standing mare and the successful use of laparoscopic electrosurgical instrumentation as the sole means of providing hemostasis to the mesovarium of a mare are described.

Low-field magnetic resonance imaging of the equine tarsus: normal anatomy

The objective of this study was to define the normal gross anatomic appearance of the adult equine tarsus on a low-field magnetic resonance (MR) image. Six radiographically normal, adult, equine tarsal cadavers were utilized. Using a scanner with a 0.064 Tesla magnet, images were acquired in the sagittal, transverse and dorsal planes for T1-weighted and the sagittal plane for T2-weighted imaging sequences. Anatomic structures on the MR images were identified and compared with cryosections of the imaged limbs. Optimal image planes were identified for the evaluation of articular cartilage, subchondral bone, flexor and extensor tendons, tarsal ligaments, and synovial structures. MR images provide a thorough evaluation of the anatomic relationships of the structures of the equine tarsus.

Standing surgical repair of cystorrhexis in two mares

Two surgical techniques were used to evert the bladder into the vagina for observation and repair of bladder tears that were associated with parturition. One technique involved an incision through the vaginal floor into the peritoneal cavity just caudal to the cervix, and prolapse of the bladder into the vagina. The second technique involved a 3-cm incision through the urethra, 5 cm cranial to the urethral orifice, and digital exploration of the tear and finger traction to evert the bladder through the urethral incision. In both mares, the bladder defects were repaired in two layers, with use of 2-0 polyglycolic acid in a simple continuous pattern. After repositioning, the vaginal and urethral incisions were closed in single layers using absorbable suture material. A standing vaginal approach eliminates the need for general anesthesia and allows excellent observation and repair of bladder tears in adult mares.

Surgical reduction of ileal impactions in the horse: 28 cases

OBJECTIVE

To evaluate the seasonal influence, signalment, type of hay consumed, clinical examination findings, and outcome after surgery for horses with ileal impaction.

STUDY DESIGN

A retrospective study.

RESULTS

Between 1988 and 1993, 28 horses had surgical correction of ileal impaction. There was a significantly higher rate of ileal impaction during the Fall (September-November, P = .0041 ). Mean duration of clinical signs of abdominal pain before referral was 15 hours. Transrectal palpation was used to localize the impaction in 11 horses. The ileal impaction was reduced by extraluminal massage aided by admixing of intestinal fluid oral to the impaction or injection of fluids intraluminally and then movement of the ingesta into the cecum alone in 24 horses. A total of 26 horses recovered from surgery; 24 horses were discharged from the hospital and eventually returned to previous use. Two horses had fatal postoperative complications: jejunocecostomy dehiscence and development of extensive small intestine adhesions after manual reduction of the impaction. One horse initially treated by manual reduction required jejunocecostomy twice for management of recurrent ileal impaction. Follow-up information was obtained for 21 horses, of which 20 were alive 1 year or longer after surgery. A total of 27 of 28 horses were fed Coastal Bermudagrass hay as the primary type of hay consumed. A total of 9 horses continued to be fed Coastal Bermudagrass hay as the only roughage source, whereas 6 horses were fed Coastal Bermudagrass with at least 50% other hay, and in 6 horses, Coastal Bermudagrass hay was entirely eliminated from the diet.

CONCLUSION AND CLINICAL RELEVANCE

Ileal impactions can be successfully reduced by celiotomy and extraluminal massage and injection techniques to soften the ingesta for passage into the cecum without enterotomy or bypass techniques in most horses. Changes in weather and feeding practices in the Fall may account for an increased risk of ileal impaction in horses in the southeastern United States at that time of year.

Ovariectomy of granulosa cell tumors in mares by use of the diagonal paramedian approach: 12 cases (1989-1995)

OBJECTIVE

To describe the short- and long-term survival rates in horses undergoing ovariectomy for granulosa cell tumors by use of the diagonal paramedian approach.

DESIGN

Retrospective case study.

ANIMALS

12 horses with granulosa cell tumors.

PROCEDURE

A diagonal paramedian approach for unilateral ovariectomy was used for removal of each mare's granulosa cell tumor. Information about complications and outcomes was analyzed.

RESULTS

Only minimal complications were detected postoperatively when the diagonal paramedian approach was used, regardless of the preferred technique for ovarian pedicle ligation or incisional closure and the use of pre- and postoperative medications. Clinical signs of moderate or severe postoperative abdominal pain were not evident in any of the 12 horses. Short- and long-term survival rates were 100%.

CLINICAL IMPLICATIONS

The diagonal paramedian approach was advantageous for ovarian tumor removal, because the ovary was immediately adjacent to the body wall at a portion of the incision site. Size of the ovary was not a limitation, because muscle tissues at the edges of the incision were flexible and easily retractable. All of these factors improved exposure, decreased traction on the ovary, increased our ability to observe the vasculature, and decreased postoperative morbidity, aiding in the removal of granulosa cell tumors in mares.

Immunolocalization of stromelysin, tumor necrosis factor (TNF) alpha, and TNF receptors in atrophied canine articular cartilage treated with hyaluronic acid and transforming growth factor beta

OBJECTIVE

To evaluate the ability of hyaluronic acid (HA), with and without transforming growth factor beta (1GF-beta), to stabilize the catabolic processes associated with atrophy of articular cartilage.

ANIMALS

20 adult, skeletally normal, hound-type dogs.

PROCEDURE

Dogs (20 to 30 kg) were randomly assigned to 1 of 5 groups. One group served as untreated controls. Bivalve casts were placed on the left hind limbs of the remaining 16 dogs to limit weightbearing and motion of the limb for 92 days. One group served as the cast control. Beginning on day 56, 3 groups received aseptic intra-articular injections in the left stifles of either 5 mg of HA or 5 mg of HA containing either 20 or 50 micrograms of TGF-beta. Intraarticular injections were repeated at 4-day intervals until the end of the study. Or day 92, stifles were harvested at necroscropy. Medial femoral condyle were histologically processed, and the articular cartilage was stained for the presence of proteoglycans, stromelysin, tumor necrosis facto (TNF) alpha, and TNF receptors (p55 and p75).

RESULTS

Decreased metachromasia was evident in the cartilage matrix of all cast groups, with the smallest decrease in the HA-treated group. Stromelysin was immunolocalized in articular cartilage of the cast (left) limbs of cast control and both HA/TGF-beta-treated groups. TNF-alpha was localized in articular cartilage of all cast (left) and right limbs, except those of the HA-treated group. Receptors for TNF were observed in both limbs of untreated control and cast control groups and cast limbs of HA/TGF-3-treated groups. The receptors were not localized in the right limbs of the HA with or without TGF-beta-treated groups. TGF-beta did not decrease stromelysin or TNF-alpha or receptors at the doses used.

CONCLUSIONS

HA may mediate a chondrostabilizing influence on articular cartilage by down-regulating TNF-alpha importantly. HA appeared to exert its inhibitory influence on TNF-alpha, as well as stromelysin and TNF receptors, on a systemic basis.

CLINICAL RELEVANCE

Results provide insight into the mode of action of HA as a therapeutic agent for arthritis and its stabilizing influence on cartilage metabolism.

Immunohistochemical analysis of an equine model of synovitis-induced arthritis

OBJECTIVES

To use lipopolysaccharide (LPS) to create synovitis in the midcarpal joint of ponies, and to assess the morphologic, histochemical, and immunohistochemical effects of synovitis on articular cartilage of the third carpal bone.

ANIMALS

2- to 3-year-old ponies, 6 control (group 1) and 6 treated (group 2).

PROCEDURE

Synovitis was induced in 1 midcarpal joint of group-2 ponies by intra-articular injections of LPS (0.02 micrograms/kg of body weight), morphine (0.1 mg/kg), and saline solution (group 2a) and a morphine and saline solution alone in the contralateral midcarpal joint (group 2b). Articular cartilage sections and attached synovial membrane from the third carpal bones were examined by immunohistochemical distribution of interleukin 1 beta, tumor necrosis factor (TNF)-alpha, TNF receptors (P55, P75) and 3-B-3(-) epitopes, and by localization of proteoglycans (metachromatic staining). Proteoglycan extracts were assessed by metachromatic staining or western blotting and immunohistochemical staining, using anti-3-B- antibodies.

RESULTS

Enhanced immunoreactivity for the cytokines and receptors was found in inflamed synovial membrane and noncalcified cartilage (group 2a more than 2b). Metachromasia of the noncalcified cartilage was greater in group-1 than in group-2a and group-2b specimens. In group 2a, chondrocyte hypertrophy and enhanced immunoreactivity for 3-B-3(-) epitope in areas of increased cytokine immunoreactivity suggested possible phenotypic change of the chondrocytes in response to synovitis. Immunohistochemical analysis by western blotting of proteoglycan extracts indicated strong 3-B-3(-) epitope immunolocalization in group-2a, weaker staining in group-2b, and barely detectable stain in group-1 specimens, which correlated with in situ immunolocalization.

CONCLUSIONS

Intra-articular administration of LPS may be used to induce a synovial environment conductive to increased immunoreactivity of interleukin 1 beta, TNF-alpha, and its receptors in equine synovial membrane and articular cartilage. These cytokines may be involved in the early phenotypic change of chondrocytes that is believed to occur in osteoarthritis and is characterized in this study by enhanced 3-B-3(-) epitope immunoreactivity and chondrocyte hypertrophy.

A comparison of laparoscopic and belt-loop gastropexy in dogs

A simplified technique for laparoscopic gastropexy (group 1) was compared to belt-loop gastropexy (group 2) in eight adult male dogs randomly divided into two groups of four dogs each. Our hypothesis was that a satisfactory laparoscopic gastropexy would approximate the strength and operative time required for belt-loop gastropexy. Operative time, surgical complications, postoperative morbidity, gross and histological appearance, radiographic microvascularization, and maximal tensile strength were measured and compared between the two groups. All dogs recovered from surgery. No morbidity was associated with either procedure. The mean (+/- SD) duration of surgery was 69.75 +/- 7.23 minutes for group 1 and 58.75 +/- 7.63 minutes for group 2. Fifty days after surgery, the microvascular appearance of the gastropexy site was similar for both groups. Blood vessels were observed within each seromuscular flap but vascular ingrowth to the abdominal musculature was observed in only two dogs, one from each group. The maximum tensile strength at 50 days was 76.55 +/- 22.78 for group 1 and 109.21 +/- 22.29 N for group 2. Differences between surgical duration and maximum tensile strength were not statistically significant (P > .05). Histologically, all gastropexies consisted of an adhesion composed of dense fibrous connective tissue. The results of this study indicate that laparoscopic gastropexy provides a minimally invasive alternative to open abdominal prophylactic gastropexy in dogs.

Medical treatment of horses with ileal impactions: 10 cases (1990-1994)

OBJECTIVE

To evaluate clinical and laboratory findings for horses treated medically for ileal impactions.

DESIGN

Retrospective case series.

ANIMALS

10 horses with primary ileal impaction that were treated successfully with medical treatment alone.

PROCEDURE

Medical records were reviewed for all horses with naturally developing ileal impaction seen at our hospital between 1990 and 1994.

RESULTS

Transrectal palpation revealed an impaction in the midabdominal area in all horses. Generalized distention of the small intestine was evident in 6 horses, whereas 4 horses were examined early in the course of the condition and did not have intestinal distention. Treatment consisted of intravenous administration of a balanced electrolyte solution, nasogastric intubation and siphonage, and administration of analgesics. Mineral oil was administered after gastric reflux had ceased. Mean time for resolution of ileal impaction was 11.7 hours.

CLINICAL IMPLICATIONS

Medical treatment may be a viable alternative for horses that cannot have surgery, provided persistent signs of severe pain or progressive gaseous distention of the small intestine are not features of the condition. Improvement of cardiovascular status, reduction in signs of abdominal pain, decrease in distention of loops of small intestine during repeated transrectal examination, softening of the impaction, and decreases in amounts of gastric reflux were indicative of a response to medical treatment.

Specificity of bronchoalveolar lavage for the diagnosis of fat embolism syndrome

The diagnosis of fat embolism syndrome (FES) is relatively difficult because simple, quantitative criteria have been lacking. The results of a recent study, however, suggest that the diagnosis of FES can be made if more than 5 per cent of the cells in fluid obtained by bronchoalveolar lavage are lipid-laden. Our study was designed to assess the specificity of this lipid staining test of bronchoalveolar cells for diagnosing FES in a series of patients coming to the pulmonology clinic. Thirty-four consecutive patients with suspected pulmonary diseases, but not FES, underwent routine bronchoscopy. Bronchoalveolar fluid was applied to slides, fixed with formalin, and stained with oil red 0. Three hundred consecutive cells of each specimen were observed for red-staining droplets. More than 5 per cent of bronchoalveolar lavage cells stained for lipids in 25 of the 34 subjects. The calculated specificity, assuming a negative finding is defined as < or = 5 per cent lipid-laden cells in the sample, was 26.5 per cent. We conclude that staining of bronchoalveolar lavage cells for lipids is not a specific test for FES.

Evaluation of peritoneal fluid following intestinal resection and anastomosis in horses

Postoperative abdominal fluid changes were compared in 2 groups of horses; those undergoing double small-colon resection and anastomosis (n = 10) and those undergoing exploratory celiotomy alone (n = 5). Peritoneal fluid was collected before surgery and on postoperative days 1, 3, 5, and 7. Total and differential nucleated cell counts, RBC numbers, and total protein and fibrinogen concentrations were evaluated. In both groups, all values were significantly higher than normal on the first postoperative day (after small-colon resection and anastomoses, WBC = 130,350 +/- 23,310 cells/microliters, RBC = 7,389,000 +/- 6,234,000 cells/microliters, total protein = 3.63 +/- 0.16 g/dl; after exploratory celiotomy alone, WBC = 166,620 +/- 34,340 cells/microliters, RBC = 295,000 +/- 86,070 cells/microliters, total protein 4.38 +/- 0.54 g/dl). The number of total peritoneal nucleated cells and RBC significantly decreased after the first postoperative day, whereas total protein and fibrinogen concentrations, percent neutrophils, and percent mononuclear cells remained unchanged. None of the values had returned to normal by postoperative day 7 (after small-colon resection and anastomoses, WBC = 45,600 +/- 8,765 cells/microliters, RBC = 95,390 +/- 53,380 cells/microliters, total protein = 4.39 +/- 0.23 g/dl; after exploratory celiotomy alone, WBC = 43,340 +/- 7,746 cells/microliters, RBC = 12,860 +/- 11,790 cells/microliters, total protein = 3.92 +/- 2.20 g/dl.) The resection and anastomosis group had a significantly lower total protein concentration on the first postoperative day and a significantly higher mean total RBC count over the entire 7-day postoperative evaluation than did horses that underwent celiotomy alone. Other values in the 2 groups of horses did not differ significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

Mistaken diagnoses in continuous muscle fiber activity of peripheral nerve origin

The syndrome of continuous muscle fiber activity of peripheral nerve origin has manifestations that resemble those of many other more common neurologic disorders during childhood and infancy. This similarity often leads to misdiagnosis when an adequate index of suspicion is not entertained and a comprehensive electromyographic examination is not performed. Two affected patients from 1 family are reported to illustrate the type of diagnostic errors that were made before the establishment of the correct diagnosis.

Comparison of staple and suture techniques for end-to-end anastomosis of the small colon in horses

Two techniques for end-to-end anastomosis of the small colon were evaluated in each of 6 horses. A simple interrupted suture pattern that excluded the mucosa and was oversewn with an inverting suture was compared with a triangulated double-row pattern of stainless steel staples. Anastomotic sites were evaluated at 2 weeks, 2 months, and 6 months for extent of abdominal adhesions, lumen diameter at anastomotic sites, bursting pressures, and healing response. Clinical postoperative complications were not associated with either technique. At postmortem examination, there was extensive adhesion formation from the mesocolon to the stapled anastomotic site. The suture technique resulted in greater luminal diameters (P less than or equal to 0.05), with good apposition of the tissue layers. Staples were missing as early as 2 weeks after surgery, and their loss was associated with separation of the muscularis at later evaluation periods. Regardless of technique, all but one anastomotic segment burst away from the anastomotic site along the mesenteric taenial band. For the 12 anastomoses performed in normal horses, the suturing technique was better than the stapling technique because of significantly larger lumen diameters, better anastomotic healing, and minimal intra-abdominal adhesion formation.

Evaluation of three techniques for end-to end anastomosis of the small colon in horses

In an attempt to determine the best method for surgical removal of devitalized small colon lesions, 12 horses underwent a double small colon resection and end-to-end anastomosis. In 4 horses (study 1), an appositional single-layer (APP-1) suture pattern was compared with an inverting 2-layer (INV-2) suture pattern. In 8 horses (study 2), an appositional 2-layer (APP-2) suture pattern was compared with the INV-2 suture technique. Polydioxanone suture (size 1-0), was used. Horses were evaluated at necropsy 3, 10, 14, 28, or 56 days after surgery. Postoperative complications (peritonitis, impaction, or excessive adhesions) were encountered in 100, 42, and 13% of the APP-1, INV-2, and APP-2 anastomoses, respectively. Postmortem evaluation of the small colon revealed dehiscence of the anastomotic site, diffuse peritonitis, and adhesion formation in 3 of the 4 horses in which the resection line was closed with the APP-1 pattern. With the INV-2 and APP-2 techniques, more intestinal inversion was present in the nontaenial than in the taenial portion of the small colon. More postoperative impactions were found with the INV-2 (n = 5) anastomoses than with the APP-2 (n = 1) technique; this appeared to be the result of excessive tissue inversion. There was no difference in lumen diameter between the INV-2 and the APP-2 techniques (P greater than or equal to 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Headaches in childhood

Childhood headache is a common problem. The approach to evaluation and therapy is similar to that in adults with the exception that the differential is slightly altered and varies by age. Methods of evaluation have been proposed based on the time course of the illness as well as on pathophysiologic considerations. Although serious intracranial disease needs to be ruled out, in most cases chronic recurrent headache of childhood represents migraine. When doubt exists, close follow-up for 4 to 6 months should clarify the issue. Migraine variants are described that are uncommon or not seen in adults, and their differential diagnosis is discussed. The most difficult differential is between that of migraine and seizures. Variations in history and associated findings are described to help in the diagnosis of seizure versus migraine. Finally, methods of treatment are given based on my experience and review of the current literature. Many patients with migraine will improve over time regardless of what is done, and this should be kept in mind when treating these patients.

Surgical correction of intermittent upward fixation of the patella in a brahman cow

Images

Herniation of the abdominal wall in pregnant mares

Abdominal wall hernia was detected in 4 pregnant mares. Antemortem diagnosis of the specific abdominal wall lesion was difficult. Ventral deviation of the abdomen, associated abdominal wall edema, and pain indicated rupture of the prepubic tendon. Three mares examined at necropsy did not have a rupture of the prepubic tendon but did have herniation of the abdominal wall. Abdominal pain was severe and was compounded by incarceration or entrapment of viscus.

Effects of xylazine on renal function and plasma glucose in ponies

The intravenous administration of xylazine (1.1 mg/kg bodyweight) in six ponies resulted in a significant increase in urine output over two hours, with maximum flow occurring between 30 and 60 minutes after injection. Urine specific gravity, osmolality and glucose concentration decreased. Renal clearance of endogenous creatinine was unchanged. Significant increases in the excretion of potassium and chloride occurred. Plasma glucose concentration was increased 30 minutes after the administration of xylazine by a mean value of 37 per cent. Serum osmolality and sodium, potassium and chloride concentrations remained unchanged.

The pneumoconioses

The pneumoconioses are by and large industrial diseases, although casual contact may be important on occasion, particularly with asbestos. The effect of dust on the lung ranges from only radiographic changes to severe functional impairment. Destruction and fibrosis of lung parenchyma may be the end result in severe disease. Great improvement has been made in recent years in the control of dust in the numerous situations where it may cause disease. We are still faced with evaluating existing standards of particle concentration in air breathed by workers and establishing safe limits and better control of the particles placed into the general environment. Undoubtedly, there are other particulates which potentially can cause lung disease of which we are not aware. Of even more concern is the realization that a latent period of 20 years or so may be necessary for physicians to become aware of the pathologic process. Every physician who sees patients with pulmonary problems must inquire regarding a history of dust exposure and be prepared to interpret that history.

Transbronchial biopsy via flexible fiberoptic bronchoscope; results in 164 patients

The diagnostic accuracy and complication rate of transbronchial forceps lung biopsy combined with bronchial brushing were analyzed in 164 consecutive patients, of whom 95 had nonmalignant disease and 51 had malignant disease. Eighteen patients with abnormal chest radiographs had normal transbronchial forceps lung biopsies and no established diagnosis. Satisfactory specimens were obtained in 153 patients (93 per cent), with diagnositc accuracies of 62, 64, and 67 per cent, respectively, in infectious, interstitial, and malignant lung disease. The over-all diagnostic accuracy was 57 per cent. Seven patients were diagnosed as having metastatic carcinoma to the lung by transbronchial forceps lung biopsy, but brush biopsy was psoitive in only 3. Of the 23 patients with primary lung carcinoma diagnosed by transbronchial forceps lung biopsy, 21 had positive brush biopsies. An additional 3 patients with bronchogenic carcinoma, however, were diagnosed only by brush biopsy. Fluoroscopy was essential for accurate positioning of the biopsy instrument. Increased risk factors were present in 83 patients (51 per cent), among whom the immunosuppressed group presented special problems. Significant bleeding in 15 patients (9 per cent) was controlled by conservative management. Pneumothorax occurred in 7 patients (4 per cent). There were no deaths. Transbronchial forceps lung biopsy in experienced hands is safe and well tolerated. The physician, nevertheless, must be prepared to handle major complications, especially bleeding. The procedure has a resonable diagnostic yield in high-risk patients who have a variety of lung lesions.