A biosignature suite from cave pool precipitates, Cottonwood Cave, New Mexico.

Calcite cave pool precipitates often display a variety of potential biosignatures from the macroscopic to the submicroscopic. A fossil cave pool in Cottonwood Cave, New Mexico, exhibits older stalactites and stalagmites that are completely coated in brown, laminated calcitic crust that extends down as pool fingers and u-loops. The pool fingers and u-loops are mainly micrite to clotted micrite, some recrystallized to microspar, with some isopachous spar layers. Micrite, particularly clotted micrite, is usually interpreted by carbonate workers as microbial in origin. Scanning electron microscopy examination of etched pool fingers, u-loops, and the brown crust revealed abundant calcified microbial filaments and biofilm. Energy dispersive X-ray analysis showed that these features have excess carbon, above that found in pure calcite. Independent carbon analysis indicated that these same samples contain up to 0.2% organic carbon. Since pool fingers hang down but form underwater, we hypothesize they are biogenic with hanging microbial filaments or biofilm acting as nuclei for calcite precipitation. Because of the abundance of micrite and fossil filaments, we further hypothesize that these pendant features formed during a period of plentiful nutrients and active hydrological activity when the pool was literally dripping with microbial slime. Although each of these lines of evidence could be interpreted in other ways, their combined weight strongly suggests the cave pool precipitates in Cottonwood Cave are biogenic. These investigations can be used to help inform extraterrestrial life-detection studies.

The laterality of the surgical correction of forefoot pathology.

UNLABELLED: Lateral prevalence has not been traditionally attributed to the development and presentation of pathologic forefoot complaints. The objective of this study was to determine if a laterality prevalence exists for surgically corrected forefoot deformities. All cases performed at the Inova Fairfax Hospital Ambulatory Surgery Center over a 76-month period were reviewed and classified into the following categories: hallux abductovalgus deformity correction, hallux limitus deformity correction, specific digital deformity correction, neuroma surgery, and combinations of these categories (n = 1821). Our analyses indicated no laterality difference in the surgical correction of most common forefoot pathologies. A measure of all examined surgical corrections (hallux abductovalgus, hallux limitus, digital deformity, and/or neuroma) did not demonstrate a difference between the surgical correction of the right and left extremities (chi(2) = 0.003; P = .94). There was also no significant difference in the surgical correction of the right and left extremities when studying the individual categories of any hallux abductovalgus correction (chi(2) = 0.416; P = .52), any hallux limitus correction (chi(2) = 2.050; P = .15), any digital deformity correction (chi(2) = 1.251; P = .26), or any neuroma surgery (chi(2) = 0.784; P = .38). Only the surgical correction of hallux limitus deformity without surgical correction of digital deformity or neuroma demonstrated a significant laterality with surgical correction of the right lower extremity being more common (chi(2) = 4.600; P = .03). LEVEL OF EVIDENCE: 2.

Gabapentin for the treatment of ethanol withdrawal.

Benzodiazepines (BZDs) are the drug of choice for the suppression of alcohol withdrawal symptoms. Gabapentin, a drug approved for use as adjunctive therapy in the treatment of partial seizures, has none of the BZD-type difficulties (drug interactions, abuse potential). We retrospectively report on the use of gabapentin for ethanol withdrawal in 49 patients. Thirty-one patients were treated in the outpatient program and 18 in the general inpatient psychiatric unit. Positive outcomes as evidenced by completion of gabapentin therapy were achieved in 25 out of 31 outpatients and 17 out of 18 inpatients. Statistical significance was reached regarding the positive relationship between prior ethanol use and inpatient "as needed" benzodiazepine use. Both sets of data suggest that gabapentin works well for the mild to moderate alcohol withdrawal patient.

Transperitoneal laparoscopic radical prostatectomy.

The diagnosis of prostate cancer for any male of any age can profoundly affect his life and that of his family. Improvements in laparoscopic devices, combined with associated surgical equipment and innovative urologic uses, have changed the treatment choices and outcomes for these types of patients. Transperitoneal laparoscopic radical prostatectomy (TLRP) offers improved postoperative outcomes for patients with localized prostatic cancer, decreasing the profound postoperative effects on functional return and potency. Quantitative advantages of TLRP include increased safety, lower hospital costs, and length of stay, while qualitative advantages include increased patient satisfaction, accelerated recovery, and qualitatively improved functional return.

Surface form typicality and asymmetric transfer in episodic memory for spoken words.

A series of experiments was conducted to determine whether the typicality of the surface form of speech would affect memory retention of spoken words. For each surface characteristic studied, a continuous-recognition-memory task was used in which listeners based recognition judgments on word identity alone. For "typical" items, repetition benefits did not depend on whether the surface forms of the 1st and 2nd occurrences matched or mismatched. For "atypical" items, a larger repetition benefit occurred when the surface forms of the 2 occurrences matched. These results suggest that episodic memory for spoken words may be directly related to the perceived typicality of particular surface characteristics.

Management of disc-associated wobbler syndrome with a partial slot fenestration and position screw technique.

A previously unpublished surgical technique for the management of disc-associated wobbler syndrome is described. A series of 17 middle-aged dobermanns (mean age 7.4 years) with this condition were managed by a technique of partial slot fenestration and position screw fixation of the affected disc space (C6/7 in all cases). One patient was lost to follow-up and, of the remaining 16 cases, 13 improved following surgery (81 per cent). The three failures were a consequence of incorrect placement of one of the screws. Careful evaluation of immediate postoperative radiographs allows this problem to be identified; the screw can then be correctly repositioned with an immediate return to surgery.

Femoral neck metaphyseal osteopathy in the cat.

This paper describes 17 cats that developed an idiopathic necrosis of the femoral neck. In four cats the lesions were bilateral when they were first examined and five cats developed lesions in the other limb within five months. They were all male cats, two years old or younger, and 15 had been neutered. The initial sign was a vague lameness which typically progressed, often acutely, to a more severe lameness. Radiography demonstrated radiolucency and loss of definition within the proximal femoral metaphysis, the femoral neck. In 12 cases there was a complete radiolucent line across the femoral neck. An excision arthroplasty was carried out on all the affected hips and the lameness resolved in all cases. The clinical and radiological signs suggest a primary bone resorption with secondary fracture of the femoral neck. The lesions have some similarities with Legg-Calve-Perthes' disease, traumatic fracture of the femoral neck, canine metaphyseal osteopathy, bacterial osteomyelitis and experimental feline herpes virus osteomyelitis.

Synthesis and biological evaluation of a series of tyrphostins containing nitrothiophene moieties as possible epidermal growth factor receptor tyrosine kinase inhibitors.

A series of 36 nitrothiophene tyrphostins were synthesized, 32 of which were novel structures. Their ability to inhibit the epidermal growth factor (EGF) receptor tyrosine kinase was assessed in a cell-free assay. Compounds containing a dinitrile, 2-aminoethene-1, 1-dinitrile or a thioamide group were good inhibitors of the receptor tyrosine kinase. Although anti-proliferative and cytotoxic activity was seen, no evidence of inhibition of EGF receptor autophosphorylation in intact cells was observed. The compounds showed no preferential inhibition of EGF-dependent proliferation of fibroblasts transfected with the EGF receptor. Furthermore, in a panel of squamous cell carcinoma cell lines with varying levels of EGF receptor expression, there was no selective cell kill of lines with the highest EGF receptor expression. The 2-nitro-5-substituted-thiophenes and the 2-nitro-3-substituted-thiophenes showed reduction potentials falling within the range likely to be reduced by cellular reducing agents, while the 2-nitro-4-substituted-thiophenes and 4-nitro-2-substituted-thiophenes did not. Compounds from the 2-nitro-5-substituted-thiophene series were shown to induce DNA damage, while no evidence of DNA damage was demonstrated with compounds from the 2-nitro-4-substituted-thiophene series. The 2-nitro-5-substituted-thiophene compound 4 showed significant tumour-type selectivity in the US National Cancer Institute human tumour cell line panel. The leukaemia cell lines were particularly sensitive to the compound, as were the majority of the colon cancer, melanoma and breast cancer cell lines, while the central nervous system-derived lines and the non-small cell lung cancer lines were particularly resistant. Further work is required to determine the precise mechanisms involved in these effects.

Valsalva maneuver in obstetrics: the influence of peripheral circulatory changes on function of the pulse oximeter.

Strenuous expulsive efforts involving sequential Valsalva maneuvers may result in maternal hypoxemia during the second stage of labor. Pulse oximetry has been used to assess oxygen saturation in laboring parturients, and this study was undertaken to evaluate the performance of the pulse oximeter (Nellcor) during the Valsalva maneuver. In both pregnant patients and nonpregnant volunteers, there were consistent interruptions in the transmission of oxygen saturation data during the Valsalva maneuver. To determine the physiologic events associated with this monitoring interruption, occlusive venous impedance plethysmographs and pulse volume amplitude recordings were obtained in volunteers performing the Valsalva maneuver. A marked decrease in pulse volume amplitude was noted, which adversely affected the oximeter's ability to distinguish physiologic arterial pulsations from background noise. Each Valsalva maneuver was associated with abrupt and transient changes in peripheral vascular volumes, thus presenting the oximeter with a rapidly changing signal for analysis that violated predetermined software criteria for pulse uniformity and caused an interruption in data transmission. The authors conclude that the Valsalva maneuver interferes with the ability of pulse oximeter technology to provide useful oxygen saturation data.

Acute suppurative thyroiditis caused by Eikenella corrodens.

Eikenella corrodens is a slow-growing facultative anaerobe present in the normal oral flora. Two children have been described with acute suppurative thyroiditis with E corrodens as the major pathogen. Staphylococci are the most frequently identified pathogens in acute suppurative thyroiditis. Penicillin or ampicillin are the drugs of choice for infections caused by E corrodens. Anatomic defects should be searched for in children with acute suppurative thyroiditis.