Spontaneous resolution rate of grade 1 cervical intraepithelial neoplasia in a private practice population.

OBJECTIVE: The purpose of this study was to assess the rate of spontaneous resolution of grade 1 cervical intraepithelial neoplasia in a private practice patient population. STUDY DESIGN: One hundred consecutive women with biopsy-proven grade 1 cervical intraepithelial neoplasia were offered expectant management in the form of repeat Papanicolaou smears every 3 months up to 1 year or treatment. Women with inadequate colposcopic examination, positive endocervical sampling, or discordant Papanicolaou smears were excluded. RESULTS: Eighty-nine (89%) women agreed to undergo expectant management. Of these, 67 (75.3%) experienced spontaneous resolution of lesions on the basis of 2 subsequent and consecutive normal smears corroborated by colposcopy. The median time to resolution was 9 months (n = 38). Seventeen (19.9%) women were treated at 1 year for persistent atypical squamous cells of undetermined significance or low-grade squamous intraepithelial lesions by loop electrosurgical conization. Of these, 1 (1.1%) had a more advanced lesion (grade 2 cervical intraepithelial neoplasia). Four (4.5%) had progression before 1 year and were treated. Only 1 (1.1%) patient was lost to follow-up. CONCLUSION: Expectant management of grade 1 cervical intraepithelial neoplasia is safe and cost-effective in a reliable patient population.

Indomethacin blunts ethchlorvynol-induced pulmonary hypertension but not pulmonary edema.

Ethchlorvynol (10 mg/kg) causes transient pulmonary hypertension and an increased permeability pulmonary edema in sheep. To determine the role of cyclooxygenase and its metabolites, histamine, and catecholamines in both phenomena, we studied five groups of sheep: group I, placebo; group II, ethchlorvynol; group III, indomethacin with ethchlorvynol; group IV, diphenhydramine with ethchlorvynol; group V, phentolamine with ethchlorvynol. Indomethacin, but not diphenhydramine or phentolamine, blunted the pulmonary hypertensive response seen immediately following the ethchlorvynol injection. However, none of the drugs had any effect on the increased permeability pulmonary edema. We conclude that cyclooxygenase or its metabolites partially mediates the hypertensive response but not the increased permeability pulmonary edema seen in sheep following ethchlorvynol injection.

Survey for heartworm, Dirofilaria immitis, and Dipetalonema reconditum (Nematoda:Filarioidea) in dogs from Virginia and North Carolina.

Random-source dogs (n = 100) in Virginia and North Carolina were surveyed for the microfilariae of Dirofilaria immitis. Microscopic examination of fresh thin-films and modified Knott preparations were made. Dirofilaria immitis and Dipetalonema reconditum were found in 19% and 6% of the animals, respectively. There was no animal that harbored both species. Prevalence was significantly higher in North Carolina (28.6%) than in Virginia (13.6%) (P less than 0.025). Mean PCV was significantly lower (P less than 0.005) in infected vs noninfected animals.

Transient pulmonary hypertension from the intravenous injection of crushed, suspended pentazocine tablets.

We describe a patient with biopsy-proven pulmonary talc granulomas (secondary to the long-term intravenous injection of crushed tablets of pentazocine) who had two episodes of transient pulmonary hypertension following the injection of this oral medication. We established a canine model and measured the right lymph duct flow, mean pulmonary arterial pressures, and pulmonary vascular resistance to determine the short-term effects on hemodynamics and the flow of lymph after intravenous administration of crushed pentazocine tablets (3 to 4 mg/kg of body weight) or pure talc (2.5 to 3 mg/kg). A typical response to both agents consisted of short-term elevations of mean pulmonary arterial pressure and pulmonary vascular resistance to approximately twice baseline values, with a slow decrement over 30 to 45 minutes. The average flow of lymph tripled, peaking at approximately two hours after injection. The lymph contained high levels of albumin. We concluded that the talc filler in oral tablets of pentazocine induces the pulmonary hypertension, probably by mechanical obstruction of the pulmonary vasculature. Association with this transient pulmonary hypertension is an increase in the permeability of the pulmonary microvasculature.

Increases in lung lymph and albumin clearance with ethchlorvynol.

We studied anesthetized dogs with right lymph duct (RLD) preparations and measured lymph flow, albumin concentrations in lymph (L) and plasma (P), pulmonary artery pressure (PAP), and pulmonary capillary wedge pressure (PCWP). Intravenous (iv) injection of ethchlorvynol (15-25 mg/kg) was followed by significant (p less than 0.02) increases in right lymph duct flow from 0.9 +/- 0.3 to 5.4 +/- 1.6 ml/h with stable PAP, PCWP, and L/P albumin (0.8 +/- 0.05 and 0.9 +/- 0.1). Similar results in RLD flow were obtained in dogs given 1) diphenhydramine, 3 mg/kg iv loading dose and 1.5 mg.kg-1 .h -1 infusion; 2) indomethacin, 4 gm/kg iv loading dose and 4 mg.kg-1h-1 infusion; 3) methylprednisolone, 30 mg/kg iv; 4) cyclophosphamide (40 mg/kg iv) to induce leukopenia (900 WBC/mm3) prior to ethchlorvynol injection. Cardiac lymph flow increased also and cardiac L/P albumin remained stable. Total hemolytic complement remained normal. We conclude that lung vascular permeability is increased following ethchlorvynol injection. Ethchlorvynol may have a direct effect on lung vascular permeability since, unlike other experimental models, complement activation, leukocytes, prostaglandins, and histamine play insignificant roles. A "final common pathway" may not exist for all forms of increased permeability pulmonary edema.

Pulmonary microvascular and alveolar epithelial permeability characteristics in N-nitroso-N-methylurethane-injected dogs.

The subcutaneous injection of 5 to 6 mg/kg of body weight of N-nitroso-N-methylurethane (NNNMU) has been reported to cause acute alveolar injury in animals. To determine the permeability characteristics of the alveolar epithelium, we employed the in vivo saline-filled dog lung model and determined the time to 50 percent equilibration in minutes of a specific tracer in the blood and the lung model and determined the time to 50 percent equilibration in minutes of a specific tracer in the blood and the lung liquid (T 1/2) for endogenous serum albumin (MW 69,000 daltons, molecular radius 35 A) and exogenously administered 500,000 MW polydispersed dextrans (molecular radius 200 A). Compared to control animals, T1/2 decreased (permeability increased) in NNNMU-injected dogs from 3,500 +/- 100 to 682 +/- 160 minutes for albumin and from 20,000 +/- 250 to 2,790 +/- 750 minutes for 500,000 MW dextran (P less than 0.001). To determine the permeability characteristics of the pulmonary microvasculature, we employed the right lymph duct cannulation dog model and measured lymph flow/30 minutes, lymph albumin and dextran concentration, and lymph/plasma albumin and dextran ratios in control and NNNMU-injected dogs. Compared to control animals, lymph flow was significantly greater in NNNMU dogs, 2.07 +/- 1.1 vs .71 +/- .50 ml/30 minutes (P less than 0.01), respectively. We conclude that NNNMU injection increases permeability in both the alveolar epithelium and the pulmonary microvasculature.

Histamine receptor and prostaglandin synthetase blockers in ethchlorvynol-induced pulmonary edema in canines.

The injection of ethchlorvynol intravenously in humans and animals causes an increased permeability form of pulmonary edema. The proximate cause for this increased alveolar capillary membrane permeability is unknown but humoral mediators such as histamine and prostaglandins could play a role. To determine whether these agents were a factor in the altered permeability, we employed the saline-filled dog lung model and measured the flux of albumin across the alveolar capillary membrane. Following the intravenous injection of ethchlorvynol, there was a marked increase in permeability which was not altered by treatment with H1 and H2 receptor blockers or a prostaglandin synthetase inhibitor. We conclude that histamine and prostaglandins play no role in the increased permeability associated with ethchlorvynol injection.

Pulmonary alveolar epithelial permeability in surgically induced hemorrhagic pancreatitis in dogs.

The adult respiratory distress syndrome has been associated with acute pancreatitis in 5-8% of patients. to determine, in a quantitative manner, the effects of acute, hemorrhagic pancreatitis on alveolar epithelial permeability, we studied two groups of dogs (group 1 - sham-operated, 7 dogs; group 2 - surgically induced pancreatitis, 7 dogs) and measured the flux of 10,000-20,000 molecular weight dextran and albumin (69,000 molecular weight), from the blood to the saline-filled lung. Following the surgical procedure (day 1), serum amylase levels increased significantly (397 +/- 70-1,268 +/- 95 dye units) in group 2 but not in group 1. Alveolar epithelial permeability (expressed as T1/2 time in minutes to 50% equilibration between blood and lung liquid) did not increase in either group for dextrans or albumin. We conclude that experimental acute pancreatitis does not cause an increase in alveolar epithelial permeability for molecular weight substances up to 69,000 daltons.

Increased alveolar epithelial permeability with acid aspiration: the effects of high-dose steroids.

Using the in vivo, liquid-filled dog lung model, we found that aspriation of acid with a pH of 2.5 or less led to increased alveolar epithelial permeability for albumin (molecular weight, 69,000 daltons; molecular radius, 35 a) and exogenously administered, polydispersed dextrans (molecular weight, 150,000 to 170,000 daltons: approximately molecular radius, 100 a). This increased permeability occurred with a large-volume (3 to 5 ml/kg) or small-volume (1 to 1.5 ml/kg) aspirate and with acid nebulization (1 to 1.5 ml/kg). When animals were either pretreated (30 min before aspiration) or post-treated (30 min after aspiration) with 30 mg of methylprednisolone/kg of body weight, there was no improvement in the increased permeability associated with acid aspiration. We conclude that, acutely, steroids have no effect on the increased alveolar epithelial permeability associated with acid aspiration.

Effects of acid aspiration on pulmonary alveolar epithelial membrane permeability.

Employing a modification of the in vivo model of a liquid-filled canine lung, we measured the movement of substances of specific sizes (albumin, 69,000 daltons with a molecular radius of 35 A; and dextran with a molecular weight of 150,000 to 170,000 and an approximate molecular radius of 100 A) from the pulmonary capillary blood to the liquid-filled lung. A solution with a specific pH (1.5 to 4.5) was instilled into the left lung of the animals at a dosage of 3 to 5 ml/kg of body weight. For both albumin and dextran with a molecular weight of 150,000 to 170,000, the time for 50 percent equilibration between the specific substance in the blood and the same substance in the pulmonary liquid decreased significantly with instillation of pulmonary liquid with a pH of 1.5 and 2.5 but did not with a pH of 3.5 or above (P less than 0.05). In addition, since histamine has been implicated as a possible humoral mediator leading to increased permeability of alveolar membranes, the levels of histamine were measured in pulmonary liquids and blood in all groups. Levels of histamine in the pulmonary liquid (but not blood) were significantly higher in animals with instillation of liquids with a pH of 1.5 and 2.5 compared to all other groups.