Explosive motor behavior,rigidity and periaqueductal gray lesions

Rats lesioned in the periaqueductal gray (PAG) manifested explosive motor behavior (EMB) shortly after surgery. When tested 24 hours postsurgery, these animals failed to exhibit the usually observed EMB in response to an intraventricular infusion of morphine. In contrast, the lesions did not interfere with the ability of intraventricularly infused etonitazene to produce rigidity. The results suggest that the site of action for morphine-produced EMB is in the PAG and that the neural substrates for EMB and rigidity are, at least in part, anatomically distinct.     

The role of gamma-aminobutyric acid (GABA) in the regulation of ethanol and acetaldehyde self-administration

1. Laboratory rats were presented with ethanol and water in a free-choice paradigm to determine each animal's preference for ethanol.

2. Following a three week ethanol free period, it was observed that the duration of gamma-butyrolactone induced loss of righting reflex was negatively correlated to voluntary ethanol intake.

3. It was also observed that the rate of intracerebroventricular self-administration of acetaldehyde was positively correlated with the latency to gamma-butyrolactone induced loss of righting reflex.

4. These findings indicate that high ethanol drinking rats and high acetaldehyde self-administrating rats are less sensitive to the sedative action of gamma-butyrolactone.     

Hypersensitivity pneumonitis due to metal working fluids: Sporadic or under reported?

BACKGROUND: Occupational exposure to metal working fluids (MWF) is common with over 1.2 million workers in the United States involved in machine finishing, machine tooling, and other metalworking operations. MWF is a known cause of hypersensitivity pneumonitis (HP). Recent reports of outbreaks of hypersensitivity HP secondary to exposure to MWF are reported. DESIGN: Cases were identified through the Occupational Disease surveillance system in the State of Michigan and from referrals for evaluation to the Division of Occupational and Environmental Medicine at Michigan State University (MSU). Each patient underwent a clinical examination including an occupational history, lung function studies, radiographic imaging, and in some cases lung biopsies. Following the diagnosis of definite HP, an industrial hygiene investigation was carried out, which included a plant walk-through, and review of the "Injury and Illness" log. Air monitoring and microbial sampling results were reviewed. RESULTS: As part of Michigan's mandatory surveillance system for occupational illnesses, seven cases of suspected HP were identified in 2003-2004 from three facilities manufacturing automobile parts in Michigan. Each plant used semi-synthetic MWFs, and conducted a MWF management program including biocide additions. Two facilities had recently changed the MWF before the cases arose. Growth of mycobacteria was found in these two MWFs. Breathing zone samples for particulates of two employees in plant A (two cases) ranged from 0.48 to 0.56 mg/m3. In plant B (four cases), two employees' sampling results ranged from 0.10 to 0.14 mg/m3. No air sampling data were available from plant C. CONCLUSION: Hypersensitivity pneumonitis due to exposure to MWFs is under-recognized by health care providers, and current surveillance systems are inadequate to provide a true estimate of its occurrence. HP arose from environments with exposures well below the Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) for MWF, and in one case from exposures well below the National Institute of Occupational Safety and Health (NIOSH) recommended exposure limit (REL). The sporadic nature of reports of HP in relationship to MWF probably represents a combination of workplace changes that cause the disease and inadequate recognition and reporting of the disease when it does occur. Physician awareness of HP secondary to MWF and an effective medical surveillance program are necessary to better understanding the epidemiology and prevention of this disease.     

Serum dioxin, testosterone, and subsequent risk of benign prostatic hyperplasia: a prospective cohort study of Air Force veterans

BACKGROUND: Operation Ranch Hand veterans were involved in spraying herbicides, including Agent Orange, during the Vietnam War in 1962-1971; Agent Orange was contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). It has been hypothesized that dioxins may be partially responsible for an increase of male reproductive tract disorders such as testicular cancer, cryptorchidism, and hypospadias. OBJECTIVES: In this study, our objective was to assess the effect of serum TCDD concentration on the risk of development of benign prostatic hyperplasia (BPH) and on serum testosterone levels. METHODS: This study was a longitudinal, prospective cohort study made up of U.S. Air Force veterans involved in Operation Ranch Hand. Other Air Force veterans who did not spray herbicides were included as comparisons. BPH was determined by medical record review and by medical examinations conducted during the study. Data were available for 971 Ranch Hand and 1,266 comparison veterans. We investigated the relationship between BPH and serum TCDD level using the Cox proportional hazards models adjusted for testosterone levels, body mass index (BMI), and the percentage change in BMI per year. RESULTS: In univariate and multivariate analyses, the risk of BPH decreased with increasing serum TCDD in the comparison group. The multivariate risk ratio for BPH in the comparison group was 0.84 (95% confidence interval, 0.73-0.98). Excluding men with prostate cancer, inflammatory or other prostatic diseases did not substantially alter the association. Serum testosterone levels were inversely associated with serum TCDD levels in both Ranch Hand and comparison groups. CONCLUSIONS: TCDD exposure at general population levels is associated with a decreasing risk of BPH with higher exposure levels. TCDD exposure is also negatively associated with serum testosterone levels.     

Steroid-responsive nephrotic syndrome in a patient with nail-patella syndrome

Nail-patella syndrome (NPS) is a rare disorder with autosomal dominant mode of inheritance. We report a child with NPS and steroid-responsive, frequently relapsing nephrotic syndrome. The child had dystrophic nails, flexion contractures of both elbows and normal renal functions. X-rays of the knees and pelvis showed hypoplastic patellae and iliac horns. Renal histology was unremarkable with mild focal increase in mesangial cellularity compatible with minimal change disease. Ultrastructural features of NPS including thickening of the glomerular basement membrane with electron-lucent areas were not found.     

Ectopic ganglion cyst presenting as a breast lump: a rare case report

We report a rare case of a breast lump in an 81-year-old woman. Initial investigations were inconclusive and excision biopsy of the lump was done. Histologically the mass proved to be a ganglion cyst. It is the only reported case of ectopic ganglion cyst in the literature that presented as a breast lump.     

Abdominal wall sinus: an unusual presentation of spilled gallstone

Gallbladder perforation and spillage of bile is common during laparoscopic cholecystectomy. We report a case of an abdominal wall sinus due to a spilled gallstone presenting 10 years after laparoscopic cholecystectomy.