Preventable disease in correctional facilities. Desmoteric foodborne outbreaks in the United States, 1974-1991.

BACKGROUND: Various disease outbreaks have been reported among prisoners. Recent foodborne outbreaks in correctional facilities in Georgia and Delaware prompted us to review the epidemiological characteristics of such outbreaks reported in the United States. METHODS: Foodborne outbreaks reported to the Centers for Disease Control and Prevention as part of routine surveillance from 1974 to 1991 were examined to identify outbreaks in jails, prisons, correctional facilities, and juvenile detention centers. Outbreak sizes, temporal trends, food vehicles, pathogens, and hygienic transgressions were analyzed. RESULTS: Eighty-eight desmoteric foodborne outbreaks involving 14307 cases of illness were reported from 31 states and territories. The mean outbreak size was 163 cases, compared with a mean of 31 cases for the 9107 reported outbreaks not involving prisoners. No fatalities among prisoners were reported. No pathogen was identified in 47 (53%) of the 88 outbreaks Salmonella species accounted for 15 (37%) of 41 outbreaks of known cause from 1974 to 1991, Clostridium perfringens for 14 (34%), and Staphylococcus aureus for 9 (22%). Fourteen of 15 Salmonella outbreaks occurred from 1984 to 1991. Food vehicles were reported for 63 (72%) of the outbreaks. Beef and poultry each were implicated in 9 (14%) of these, followed by fish or poultry salads and Mexican food, which accounted for 6 outbreaks (10%). Food-handling errors were reported for 69 (78%) of the 88 outbreaks. Improper food storage was reported in 62 (90%) of these. CONCLUSIONS: Foodborne outbreaks are reported regularly from correctional facilities in the United States. Outbreaks caused by Salmonella species, a special threat to prisoners with human immunodeficiency virus infection, seem to be increasing. Food production in correctional facilities should meet minimum safety standards, including sufficient refrigeration facilities, training of food handlers, and exemption of ill food handlers from work.

Anesthetic management of an incisional dehiscence in recovery following exploratory laparotomy in a horse.

A 5-year old Arabian mare fell during recovery from general anesthesia after an exploratory laparotomy. This fall resulted in dehiscence of the abdominal closure, and a substantial amount of intestines were exteriorized. Chemical and manual restraints were rapidly used to prevent trauma to the exposed intestines. A second general anesthesia was initiated to clean the intestines and close the incision. Multiple anesthetic problems were encountered, including arterial hypotension and hypoxemia. The horse recovered from the second general anesthesia and surgery, and all complications gradually resolved. The horse was discharged and has not had further problems to date.

Mechanical properties of the canine mitral valve: effects of autonomic stimulation.

Experiments were designed to determine whether the canine mitral valve actively contracts and, if so, if its mechanical activity can be modulated by the autonomic nervous system. A miniature displacement gauge was sutured to the atrial (muscular) surface of the septal leaflet in 65 dogs under pentothal sodium anesthesia during total cardiopulmonary bypass. During bypass, with blood constantly drained from the left ventricle (LV), the leaflet deflected into the LV during ventricular systole as would be expected with active contraction. With blood present in the LV, leaflet deflection was reversed, indicating a passive displacement. After application of 85% phenol to the atrial surface, ventricular displacement of the leaflet was abolished, whereas the atrial displacement was significantly augmented. There was a positive inotropic effect during sympathetic stimulation and a negative inotropic effect with parasympathetic stimulation, i.e., increased and decreased ventricular deflection, respectively. These effects of autonomic stimulation were abolished by application of phenol to the leaflet muscle. During simultaneous electrical and mechanical recordings from the valve, activation appeared to originate from the atrium, before ventricular depolarization. It was concluded that the valvular muscle actively contracts to assist in bringing the valve leaflets into early apposition. This contraction imparts a measurable level of active "stiffness" to the valve, reducing atrial displacement during ventricular systole. This "stiffness" can be modified by autonomic input and may contribute to dysfunction of morphologically normal mitral valves.

Pharmacodynamic properties of succinylcholine in greyhounds.

Succinylcholine is a depolarizing neuromuscular blocking drug, which is rapidly hydrolyzed by the enzyme pseudocholinesterase. In Greyhounds, the metabolism of certain drugs is atypical relative to other breeds, and it has been suggested that Greyhounds may be an atypical population, with lower pseudocholinesterase activity, slower hydrolysis of the drug succinylcholine, and a prolonged duration of action of the drug, compared with a mixed-breed control population. Six healthy adult Greyhounds and 6 healthy adult mixed-breed dogs were studied. Blood was drawn from each dog and analyzed for serum cholinesterase activity, and a biochemical profile was done to verify normal liver function. The dogs were anesthetized with methohexital (10 mg/kg) and isoflurane (1.25 minimal alveolar concentration) in 100% oxygen. Ventilation was controlled, fluids were administered IV (lactated Ringer solution, 10 ml/kg/h), and blood gases, blood pressure, and heart rate were monitored. The right hind limb was immobilized and a force transducer was used to monitor twitch strength of the interosseous muscle with supramaximal stimulation of the tibial nerve. Succinylcholine was administered to each dog 3 times at a dosage of 0.3 mg/kg. After drug administration, the time to 50% recovery of twitch strength (single twitch, 1/s), and 50% recovery of train-of-4 was determined. Subsequent doses were administered after complete recovery. The time to 50% recovery after succinylcholine administration in Greyhounds (38 minutes, dose 1, single twitch) was not significantly different than the time to 50% recovery in mixed-breed dogs (29 minutes, dose 1, single twitch), using either monitoring technique. Pseudocholinesterase activity was also not significantly different between the Greyhounds (1,685 mU/ml) and the mixed-breed dogs (1,588 mU/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular effects of vasopressors in halothane-anesthetized dogs before and after hemorrhage.

Exogenously administered vasopressors (sympathomimetics) were evaluated in halothane-anesthetized dogs to determine the effects of these drugs on cardiovascular function before and after hemorrhage. Six dogs were anesthetized with thiamylal sodium (20 mg/kg of body weight) and halothane (1.25 minimal alveolar concentration) in 100% oxygen. After instrumentation, cardiac output, systemic arterial blood pressure (SAP), heart rate (HR), left ventricular pressure, pulmonary arterial pressure, and an index of cardiac contractility (dP/dT) were measured. Stroke volume, cardiac index (CI), stroke index (SI), rate-pressure product, and systemic vascular resistance (SVR) were calculated. Epinephrine (0.1, 0.3, and 0.5 micrograms/kg/min [low, medium, and high doses, respectively]) and dobutamine (1, 5, and 10 micrograms/kg/min [low, medium, and high doses, respectively]) were infused. Methoxamine was given in a bolus of 0.22 mg/kg, IV. All measurements were taken at 2.5 minutes after infusion, and were repeated after removal of 40% of the estimated blood volume. Dobutamine administered at the low dose before hemorrhage increased SAP and dP/dT. At the high and medium dose, dobutamine significantly increased CI, dP/dT, and SAP, with no significant change in HR or SVR. The medium dose of epinephrine was the most effective dose of epinephrine at increasing key variables (CI, SI, dP/dT). The response of CI and SI to this dose was not significantly different from the changes seen with high-dose administration of dobutamine. The dP/dT was significantly lower with epinephrine than with dobutamine, and SVR and HR were unchanged with epinephrine, except at the low dose, which decreased SVR.

Cardiovascular effects of vasopressors in isoflurane-anesthetized dogs before and after hemorrhage.

Exogenously administered vasopressors (sympathomimetics) were evaluated in isoflurane-anesthetized dogs to determine the effects of these drugs on cardiovascular function before and after hemorrhage. Six dogs were anesthetized with thiamylal sodium (20 mg/kg of body weight) and isoflurane (1.25 minimal alveolar concentration) in 100% oxygen. After instrumentation, cardiac output, systemic arterial blood pressure, heart rate (HR), left ventricular pressure, pulmonary arterial pressure, and an index of cardiac contractility (dP/dT) were measured. Stroke volume, cardiac index (CI), stroke index (SI), rate-pressure product, and systemic vascular resistance (SVR) were calculated. Epinephrine (0.1, 0.3, and 0.5 micrograms/kg/min [low, medium, and high doses, respectively]) and dobutamine (1, 5, and 10 micrograms/kg/min [low, medium, and high doses, respectively]) were infused. Methoxamine was given in a bolus of 0.22 mg/kg, IV. All measurements were taken at 2.5 minutes after infusion, and were repeated after removal of 40% of the estimated blood volume. Before hemorrhage, administration of high doses of dobutamine and medium and high doses of epinephrine were equally effective at increasing CI and SI. The dP/dT was increased to the greatest degree by administration of high doses of dobutamine. Administration of the low dose of dobutamine increased dP/dT, whereas administration of the low dose of epinephrine increased CI, HR, and SI, and decreased SVR. The HR and SVR were not increased by administration of any dose of dobutamine or of the medium and high doses of epinephrine. However, methoxamine increased SVR and decreased HR. Methoxamine decreased CI, SI, and dP/dT, but increased systemic arterial pressure to the same degree as that attributed to administration of high doses of dobutamine and epinephrine.(ABSTRACT TRUNCATED AT 250 WORDS)

Smooth muscle cell-reticulin lamellar units of 13.2 microns thickness composing the aortic intima.

Smooth muscle cells of the aortic intima are generally of two forms, spindle and stellate. Spindle cells are typically axial in their orientation, while stellate cells lie parallel to the luminal surface; cell processes do not characteristically extend in the radial direction through the intimal thickness. Evidence is given here to suggest that these cells are clustered in layers of about 13.2 microns thickness which are separated by condensations of reticulin fibers. These layered clusters may extend as much as 1 cm to 2 cm in the axial direction. The numbers of layers appear to increase during growth and maturation to a stable value of about 12 by age 30-40. With further aging and growth of fibrous plaques, the layers seem to become thicker and to merge, obliterating their boundaries, to become 15 to 35 microns or more in average thickness. This expansion and merging of lamellar units precedes atheronecrosis and appears to represent an important precursor of the necrotic core. The greatest growth of fibrous plaques, at ages 40 to 60, takes place after the stabilization of cell numbers at ages 30 to 40, and is almost as likely to happen in the least cellular as in the most cellular places. Hence, these data suggest that smooth muscle cell numbers are not important determinants of the locations nor of the growth rates of fibrous plaques in the lateral thoracic aorta.

Altered nicotinic sensitivity of AV node in surgically denervated canine hearts.

The responses of normal and cardiac-denervated (DNV) dogs to acetylcholine (ACh) and nicotine (NIC) were examined to determine if the intrinsic cardiac nerves (ICN) that modulate electrical conduction display denervation supersensitivity. Control (n = 18) and DNV (n = 18) animals were placed on cardiopulmonary bypass. Recording of intra-atrial (P-A), intraventricular (H-V), and atrioventricular (AV) nodal (A-H) conduction times were made from the region of the His bundle. ACh (0.1-10 micrograms) was used to produce muscarinic stimulation, whereas NIC (0.1-400 micrograms) was employed to stimulate the ICN. All drugs were administered intracoronary. No supersensitivity to either ACh or NIC was seen in the data from the P-A or H-V intervals of the His electrogram in the DNV animals. However, this group displayed approximately a 10-fold increase in the negative dromotropic effect of NIC on the AV node compared with control. No significant change in muscarinic sensitivity of the AV node was observed in the DNV animals. We conclude that 1) no denervation supersensitivity of the ICN mediating effects on intra-atrial and intraventricular conduction occurs; 2) the AV node itself does not show muscarinic supersensitivity following extrinsic denervation; 3) the ICN do display denervation supersensitivity as shown by a 10-fold increase in the effects of NIC on AV nodal conduction time.

Responsiveness of intracardiac neurons to cholinergic stimulation in normal and thyroidectomized dogs.

Hypothyroidism alters the responsiveness of sympathetically innervated structures. The present work was done to determine if the responsiveness of the intrinsic cardiac nerves (ICN) to nicotine is also affected by thyroidectomy (THX). Mongrel dogs were anesthetized and an electrode catheter was advanced into the right atrium for recording His bundle activity (HB). A second cannula was placed into the carotid artery with its tip near the coronary ostia, so that the responses to the drugs injected would be confined to the heart. Changes in the A-H interval of the HB were recorded in response to both acetylcholine (ACH) 2-50 ug, and nicotine HCl (NIC) 5-100 ug, before and after beta blockade with metoprolol (1-4 mg). There were no important differences between the two groups in the responses of A-V nodal conduction to ACH over the dose range used. However, the THX animals showed an apparent increase in responsiveness to NIC; ie., ca. 5% decrease in A-H at 10 ug (control) compared to ca. 30% increase after THX. The apparent catecholamine-releasing effect of NIC was also enhanced in the THX animals. In addition, the responses to ACH and NIC were compared in animals both 'on' and 'off' cardiac bypass. The data suggest that hypothyroidism increases the effectiveness of nicotinic stimulation of intracardiac neurons.

Independence of brain and body temperatures in flying American kestrels, Falco sparverius.

Brain and body temperatures were measured via small thermocouples implanted in the anterior hypothalami and colons, respectively, of five adult American kestrels (F. sparverius, mean mass 119 g) during descending flights in a wind tunnel at angles of 4 and 6 degrees below horizontal, at 10 m.s-1 air speed, and at 23 degrees C air temperature. For comparison, temperatures were recorded from resting birds at 22.5-36.1 degrees C air temperatures. Colonic (Tc) and hypothalamic (Th) temperatures both increased after the onset of flight; steady-state levels were attained after 1 min in the hypothalamus and after 5 or more min in the colon. The steady-state difference (delta T = Tc - Th) averaged 1.2 degrees C, higher by 0.5 degrees C than delta T in resting kestrels. The establishment of delta T during flight may be correlated with increased respiratory and corneal evaporation. The response apparently confines most stored body heat to noncranial regions, thus protecting brain tissue from thermal extremes.