A global analysis of Y-chromosomal haplotype diversity for 23 STR loci

In a worldwide collaborative effort, 19,630 Y-chromosomes were sampled from 129 different populations in 51 countries. These chromosomes were typed for 23 short-tandem repeat (STR) loci (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385ab, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, GATAH4, DYS481, DYS533, DYS549, DYS570, DYS576, and DYS643) and using the PowerPlex Y23 System (PPY23, Promega Corporation, Madison, WI). Locus-specific allelic spectra of these markers were determined and a consistently high level of allelic diversity was observed. A considerable number of null, duplicate and off-ladder alleles were revealed. Standard single-locus and haplotype-based parameters were calculated and compared between subsets of Y-STR markers established for forensic casework. The PPY23 marker set provides substantially stronger discriminatory power than other available kits but at the same time reveals the same general patterns of population structure as other marker sets. A strong correlation was observed between the number of Y-STRs included in a marker set and some of the forensic parameters under study. Interestingly a weak but consistent trend toward smaller genetic distances resulting from larger numbers of markers became apparent.

Toward male individualization with rapidly mutating y-chromosomal short tandem repeats

Relevant for various areas of human genetics, Y-chromosomal short tandem repeats (Y-STRs) are commonly used for testing close paternal relationships among individuals and populations, and for male lineage identification. However, even the widely used 17-loci Yfiler set cannot resolve individuals and populations completely. Here, 52 centers generated quality-controlled data of 13 rapidly mutating (RM) Y-STRs in 14,644 related and unrelated males from 111 worldwide populations. Strikingly, >99% of the 12,272 unrelated males were completely individualized. Haplotype diversity was extremely high (global: 0.9999985, regional: 0.99836–0.9999988). Haplotype sharing between populations was almost absent except for six (0.05%) of the 12,156 haplotypes. Haplotype sharing within populations was generally rare (0.8% nonunique haplotypes), significantly lower in urban (0.9%) than rural (2.1%) and highest in endogamous groups (14.3%). Analysis of molecular variance revealed 99.98% of variation within populations, 0.018% among populations within groups, and 0.002% among groups. Of the 2,372 newly and 156 previously typed male relative pairs, 29% were differentiated including 27% of the 2,378 father–son pairs. Relative to Yfiler, haplotype diversity was increased in 86% of the populations tested and overall male relative differentiation was raised by 23.5%. Our study demonstrates the value of RM Y-STRs in identifying and separating unrelated and related males and provides a reference database.

Characterising the STR locus D6S1043 and examination of its effect on stutter rates

The forensic analysis of DNA is most often undertaken by the amplification of short tandem repeats (STR) using the polymerase chain reaction (PCR). DNA amplification can result in production of the target allele amplicon and a by-product called stutter. Stutter is the result of the miscopy of the target allele and is typically one repeat smaller. Stutter is traditionally described as a ratio of stutter and allele height; stutter ratio (SR). The challenge to DNA profile interpretation is most serious whenever stutter products are of a similar height to the minor allelic peaks in a mixed DNA profile. An accurate assignment of peaks and the prediction of their height is important when objectively interpreting forensic DNA profiles. The longest uninterrupted stretch (LUS) of tandem repeats within the allele has previously been shown to be a good predictor of stutter ratio. LUS is determined by sequencing a range of observed alleles at a locus. The locus D6S1043 is a relatively new locus to appear in commercial forensic DNA testing kits. To date however, there has been no comprehensive report of sequencing of this locus. In this work, we sequence a sample of D6S1043 alleles to determine LUS values and investigate allele repeat number and LUS as explanatory variables for SR.

Phosphorus flux from wetland ditch sediments

The accumulation of phosphorus (P) in the bottom sediment of field drainage ditches poses a threat to the ecology both of the ditch water and downstream water courses. We investigated the amounts, forms and internal loading of sediment-bound P along two drainage ditches that regulate water levels in a basin fen (~200 ha) supporting a mixture of restored wetland and drained agricultural fields. Water levels in the Lady's Drove Rhyne are currently managed to enhance the biodiversity of the wetland (Catcott Lows Reserve - an area formerly cultivated for arable crop production); whereas, the East Ditch is managed to drain adjoining land that remains under arable and livestock production. Laboratory-based chemical fractionation schemes were used to characterise the forms and potential mobility of the sediment-bound P, whilst pore-water equilibrators were employed in situ to evaluate the diffusive flux of P through the sediment-water column, and to characterise the corresponding redox conditions. Along both ditches, sediment pore-water profiles indicated conditions ranging from weakly to very reducing conditions with increasing depth, and net fluxes of P from the sediment to overlying water. P flux values ranged from 0.33 to 1.30 mg m(-2) day(-1). Both the degree of P saturation (DPS) of the sediment and NaOH extractable (Fe/Al-bound) P correlated significantly (P<0.05) with P flux. Both in the wetland and agricultural ditches, by far the highest values for P flux were recorded at sites closest to points of drainage water entry from the corresponding, adjoining land. Although the P flux data were obtained from only a single sampling event, this study highlights the contribution of historical as well as ongoing agricultural land use on the sustained elevated P status of ditch sediments in lowland catchments.

Capillary electrophoresis and 5-channel LIF detection of a 26plex autosomal STR assay for human identification

Multiplex polymerase chain reaction (PCR) is a common method used for DNA typing in forensic and paternity cases. There are numerous commercial short tandem repeat (STR) multiplex assays currently available to the forensic community. These assays amplify the core Combined DNA Index System (CODIS) STR loci for entry into the US. DNA database. Additional non-CODIS loci, which are considered genetically unlinked to the CODIS loci, can be useful in resolving challenging cases such as missing persons and mass disaster victim identification, paternity testing, and immigration testing. An STR multiplex has been successfully developed with 25 non-CODIS autosomal loci plus the sex-typing locus amelogenin for a total of 26 loci in a single 26plex amplification reaction. This chapter will focus on the preparation and the use of the 26plex assay with DNA samples for the purpose of human identification.

Biology and Genetics of New Autosomal STR Loci Useful for Forensic DNA Analysis

Short tandem repeats (STRs) are regions of tandemly repeated DNA segments found throughout the human genome that vary in length (through insertion, deletion, or mutation) with a core repeated DNA sequence. Forensic laboratories commonly use tetranucleotide repeats, containing a four base pair (4-bp) repeat structure such as GATA. In 1997, the Federal Bureau of Investigation (FBI) Laboratory selected 13 STR loci that form the backbone of the U.S. national DNA database. Building on the European expansion in 2009, the FBI announced plans in April 2011 to expand the U.S. core loci to as many as 20 STRs to enable more global DNA data sharing. Commercial STR kits enable consistency in marker use and allele nomenclature between laboratories and help improve quality control. The STRBase website, maintained by the U.S. National Institute of Standards and Technology (NIST), contains helpful information on STR markers used in human identity testing.

Authentication of African green monkey cell lines using human short tandem repeat markers

BACKGROUND

Tools for authenticating cell lines are critical for quality control in cell-based biological experiments. Currently there are methods to authenticate human cell lines using short tandem repeat (STR) markers based on the technology and procedures successfully used in the forensic community for human identification, but there are no STR based methods for authenticating nonhuman cell lines to date. There is significant homology between the human and vervet monkey genome and we utilized these similarities to design the first multiplex assay based on human STR markers for vervet cell line identification.

RESULTS

The following STR markers were incorporated into the vervet multiplex PCR assay: D17S1304, D5S1467, D19S245, D1S518, D8S1106, D4S2408, D6S1017, and DYS389. The eight markers were successful in uniquely identifying sixty-two vervet monkey DNA samples and confirmed that Vero76 cells and COS-7 cells were derived from Vero and CV-1 cells, respectively. The multiplex assay shows specificity for vervet DNA within the determined allele range for vervet monkeys; however, the primers will also amplify human DNA for each marker resulting in amplicons outside the vervet allele range in several of the loci. The STR markers showed genetic stability in over sixty-nine passages of Vero cells, suggesting low mutation rates in the targeted STR sequences in the Vero cell line.

CONCLUSIONS

A functional vervet multiplex assay consisting of eight human STR markers with heterozygosity values ranging from 0.53-0.79 was successful in uniquely identifying sixty-two vervet monkey samples. The probability of a random match using these eight markers between any two vervet samples is approximately 1 in 1.9 million. While authenticating a vervet cell line, the multiplex assay may also be a useful indicator for human cell line contamination since the assay is based on human STR markers.

STR sequence analysis for characterizing normal, variant, and null alleles

DNA sequence variation is known to exist in and around the repeat region of short tandem repeat (STR) loci used in human identity testing. While the vast majority of STR alleles measured in forensic DNA laboratories worldwide type as "normal" alleles compared with STR kit allelic ladders, a number of variant alleles have been reported. In addition, a sequence difference at a polymerase chain reaction (PCR) primer binding site in the DNA template can cause allele drop-out (i.e., a "null" or "silent" allele) with one set of primers and not with another. Our group at the National Institute of Standards and Technology (NIST) has been sequencing variant and null alleles supplied by forensic labs and cataloging this information on the NIST STRBase website for the past decade. The PCR primer sequences and strategy used for our STR allele sequencing work involving 23 autosomal STRs and 17 Y-chromosome STRs are described along with the results from 111 variant and 17 null alleles.

Concordance and population studies along with stutter and peak height ratio analysis for the PowerPlex ® ESX 17 and ESI 17 Systems

The PowerPlex(®) ESX 17 and ESI 17 Systems for short tandem repeat (STR) amplification were developed by the Promega Corporation to meet the European Network of Forensic Science Institutes (ENFSI) and the European DNA Profiling (EDNAP) Group recommendations for increasing the number of STR loci included in the European Standard Set (ESS). The PowerPlex ESX 17 and ESI 17 Systems utilize different PCR primer combinations to co-amplify the following 17 loci: D1S1656, D2S441, D2S1338, D3S1358, D8S1179, D10S1248, D12S391, D16S539, D18S51, D19S433, D21S11, D22S1045, FGA, TH01, vWA, SE33, and the sex-typing locus amelogenin. A total of 1443 U.S. population samples were evaluated with pre-commercialization versions of both kits. Stutter and heterozygote peak height ratios have been used to characterize kit performance. Typing results have been used to estimate the match probabilities provided by the chosen loci as well as in concordance studies. Full concordance between the typing results for the two kits was observed in 99.994% (49,055 out of 49,062) STR allele calls compared. All genotyping discrepancies were confirmed by DNA sequence analysis. As a result of these comparisons, a second forward primer for the D22S1045 locus has been added to the PowerPlex ESX 17 System to address a primer binding site mutation and the D1S1656 locus reverse primer in the PowerPlex ESI 17 System was modified to eliminate an amplification-efficiency reducing primer dimer.

A 26plex autosomal STR assay to aid human identity testing*

A short tandem repeat multiplex assay has been successfully developed with 25 autosomal loci plus the sex-typing locus amelogenin for a total of 26 amplified products in a single reaction. Primers for the loci were designed so that all of the amplicons present were distributed from 65 base pairs (bp) to less than 400 bp within a five-dye chemistry design with the fifth dye reserved for the sizing standard. A multiplex design strategy was developed to overcome challenges encountered in creating this assay. The limits of the multiplex were tested, resulting in the successful amplification of a wide range of genomic DNA sample concentrations from 2 ng to as low as 100 pg with 30 cycles of PCR. The 26plex has the potential to benefit the forensic community for reference sample testing and complex relationship evaluation.

Concordance Study Between the AmpF?STR�MiniFilerTMPCR Amplification Kit and Conventional STR Typing Kits

The AmpFlSTR MiniFiler polymerase chain reaction amplification kit developed by Applied Biosystems enables size reduction on eight of the larger STR loci amplified in the Identifiler kit, which will aid recovery of information from highly degraded DNA samples. The MiniFiler Kit amplifies CSF1PO, FGA, D2S1338, D7S820, D13S317, D16S539, D18S51, and D21S11 as well as the sex-typing locus amelogenin. A total of 1308 samples were evaluated with both the MiniFiler and Identifiler STR kits: 449 African American, 445 Caucasian, 207 Hispanic, and 207 Asian individuals. Full concordance between Identifiler and MiniFiler Kits was observed in 99.7% (10,437 out of 10,464) STR allele calls compared. The 27 differences seen are listed in Table 1 and encompass the loci D13S317 (n = 14) and D16S539 (n = 10) as well as D18S51 (n = 1), D7S820 (n = 1), and CSF1PO (n = 1). Genotyping discrepancies between the Identifiler and MiniFiler kits were confirmed by reamplification of the samples and further testing using the PowerPlex 16 kit in many cases. DNA sequence analysis was also performed in order to understand the nature of the genetic variations causing the allele dropout or apparent repeat unit shift.

Gamma irradiation of intravenous immunoglobulin

This paper describes gamma irradiation of a biotherapeutic product under conditions (the Clearant Process") that protect proteins and foster inactivation of viruses and other pathogens. The treated product was immunoglobulin paste from cold ethanol fractionation of human plasma, a process intermediate in the production of intravenous immunoglobulin (IGIV). The frozen paste was irradiated on dry ice to 45 kGy, conditions that inactivate > or = 4 log10 of non-enveloped viruses and > or = 6 log10 of enveloped viruses. When IGIV purified from the irradiated paste was characterized, no protein aggregation, fragmentation, oxidation or denaturation was detected and Fab functionality remained intact.

Histological study of normal and tumor-bearing liver treated with focused ultrasound

The purpose of this investigation was to study the tissue damage (including blood vessels) on both normal and tumor-bearing experimental livers and the course of liver repair after focused ultrasound (FUS) treatment using histological evaluation. A series of experiments were carried out in vivo. Tissue was treated using arrays of ultrasound exposures with a frequency of 1.7 MHz, in situ spatially averaged focal intensity (I(SAL) in situ) of 212-266 W/cm2 (corresponding to in situ spatial peak intensity of 382-479 W/cm2), 5-10 s exposure duration and 1.5-3.0 mm exposure separation. Tissue specimens were examined using both light and electron microscopy. The damage to the blood vessel walls was studied. The results showed the existence of indirect tissue damage in both normal and tumor tissue that is outside of the treatment volume, due to disruption of the major blood vessels supplying the adjacent area. Evidence for liver regeneration was found 2 months after FUS treatment.

Treatment of implanted liver tumors with focused ultrasound

This article reports treatment of implanted liver tumors (HSN fibrosarcoma) with focused ultrasound (FUS). Experiments were carried out on implanted liver tumors in vivo. In order to determine the optimum treatment conditions, various combinations of exposure parameters were investigated. The results showed that it is possible to achieve total destruction of tumor cells in the treatment volume using an FUS system with a frequency of 1.7 MHz, with in situ ISAL of 261 W/cm2, 5-s exposure duration, and 1.5-mm exposure separation, with an in situ ISAL of 266 W/cm2, 10-s duration, and 2-mm separation, or with in situ ISAL of 213 W/cm2, 8-s duration, and 1.5-mm separation. Fifteen selected tumors were treated with these experimentally determined "optimum" exposure conditions. All the tumors were destroyed completely. Assessment of tumor viability in the treated volume was performed using both histologic and tissue culture methods. The mechanism of tumor damage, the limitations of the tumor model, and the effect of exposure parameters and liver blood flow on the treatment are discussed.

A comparison of T2 and gadolinium enhanced MRI with CT myelography in cervical radiculopathy

Two MRI strategies which have been reported to be effective in assessing cervical exit foramina, were prospectively compared with CT myelography in 20 patients with cervical radiculopathy. The first strategy utilized 3D T2* images, the second gadolinium enhanced 2D T1 images. Gadolinium (dimeglumine gadopentetate, Schering Ltd) enhanced images did not confer any benefit in the investigation of this condition, probably due to enhancement of herniated disc material and osteophytes adjacent to the neurocentral joint. Three-dimensional (3D) T2* white cerebrospinal fluid images had an accuracy approaching 90% for the diagnosis of foraminal encroachment, compared with a gold standard. MRI including a 3D T2* sequence is thus an acceptable primary investigation for cervical radiculopathy, but when the findings are incompatible with clinical symptomatology, CT myelography is still indicated.

Influence of ablated tissue on the formation of high-intensity focused ultrasound lesions

In order to ablate tumours using high-intensity focused ultrasound (HIFU) it is necessary to irradiate the tumour with a confluent array of single ultrasound exposures. We have identified a phenomenon that we term lesion-to-lesion interaction, which occurs when the spatial separation of individual exposures is such that an existing lesions appears to affect the formation of a subsequent lesion. This article investigates the implications of this phenomenon for strategies to ablate large tissue volumes in the treatment of hepatic metastases. Experiments on pig and rat livers have been carried out using a focused ultrasound system with a frequency of 1.7 MHz, an in situ spatially averaged focal intensity (ISAL) of 133-658 W cm-2 (ISP of 239-1185 W cm-2) and an exposure duration of 5-15 s. The results show that there is interaction between lesions that spatial exposure separations that depend on the intensities and exposure durations used. As a result, either subsequent lesions form closer to the ultrasound source (if the focal peak of the ultrasound beam is placed deep inside the liver tissue) or their length is reduced (if the focal peak is near the liver surface). An explanation is suggested for this effect and a strategy for its avoidance during in vivo HIFU treatment is discussed.

Review article: high intensity focused ultrasound--potential for cancer treatment

The prospect of being able to use "minimally invasive" surgical techniques is of great interest today, particularly for reasons of health economics, patient acceptability and reduced morbidity. High intensity focused ultrasound (HIFU) has long been known to offer the potential of very precise "trackless lesioning" but has only recently, with the advent of high quality methods of medical imaging, become a practicable possibility. High intensity beams can readily be achieved using either bowel or lens focusing procedures and, by choice of a suitable acoustic frequency, regions of tissue destruction--"lesions"--can be induced at depths of up to at least 10 cm with exposure times of the order of 1 s. Theoretical and experimental evidence indicates that the primary mechanism of damage is thermal, i.e. "cooking" of the tissues. Both conventional cavitation and boiling of tissue water may complicate the situation. Furthermore, substantial non-linear behaviour is involved. On histological appearance the lesions have a spatially sharp demarcation between regions of normal and dead cells. When attempts are made to ablate a block of tissue, by creating an array of adjacent elementary lesions, a phenomenon is observed of inhibition of formation of a lesion whose placing is too close to that of a neighbour. Provided that this problem is dealt with, complete ablation of an extended block of tissue can be achieved. For animal tumours in particular, this observation is reinforced by evidence both of in vitro cell survival and of tumour growth delay experiments. Clinically, the sites accessible for HIFU treatment will be limited by the need for a suitably wide acoustic window that either is available naturally or can be provided by a relatively minor surgical procedure. Tumour sites which thus offer a realistic prospect for local control (and some of which are already the subject of phase 1 trials) include liver, bladder, kidney, prostate, breast and brain. There is also considerable interest in non-cancer applications in these and other sites.

Lumbosacral skin markers and identification of occult spinal dysraphism in neonates

Some skin lesions over the spine are known to be associated with occult spinal dysraphism, but the significance of common skin lesions, such as sacral pits and dimples, is uncertain. In this prospective study, 95 neonates (1.9% of 4989 live births) were referred with possible markers of occult spinal dysraphism. Seven of 94 babies examined had abnormalities demonstrated by spinal ultrasound, compared with 5 of 105 controls. In 2 of 94 and 3 of 105 of these, the conus medullaris was located at L3 but no other abnormalities were found. Of the 75 babies with a sacral dimple or pit alone, none had an abnormality, suggesting that these skin lesions do not indicate a high risk of occult spinal dysraphism.

Minimally invasive cancer surgery using focused ultrasound: a pre-clinical, normal tissue study

Using a focused 1.7 MHz ultrasound field (focal length/transducer diameter ratio of 1.7) and in situ intensities spatially averaged within the half-pressure maximum contour in the range 100-400 W cm-2, ablative lesions have been prescriptively placed singly and in arrays, in the livers and bladder walls of adult female Large White pigs. Exposures were made through the skin with up to 8 cm of intervening tissue. Ablative lesions were placed under ultrasonic guidance, and specific lesion echoes were subsequently observed in two cases. Animals were sacrificed immediately after induction of ultrasonic lesions, post-mortems were performed, as were histological examinations of normal and damaged tissue. There was clear demarcation between ablated and normal tissue. Provided that simple rules on exposure technique had been observed, there was no evidence of inadvertent tissue damage, either locally to the treatment site, or in the tissue lying between the source and the target. This study is a useful step in demonstrating the feasibility of clinical trials for the use of this technique in treating bladder tumours and solitary liver metastases.

Lesion development in focused ultrasound surgery: a general model

An analytical model has been constructed for the process of formation of thermal lesions in tissue, resulting from exposure to intense, highly focused ultrasound beams such as may be used in minimally invasive surgery. The model assumes a Gaussian approximation to beam shape in the focal region and predicts, for any such focal beam, the time delay to initiation of a lesion and the subsequent time course of growth of that lesion in lateral and axial dimensions, taking into account the effects of thermal diffusion and blood perfusion. The necessary approximations and assumptions of the model are considered. Comparison of predictions with experimentally measured data on excised pig liver indicate generally good agreement. Comparisons are also made of this theory with previously published data on exposure-time dependence of lesioning threshold intensity. Deficiencies are identified in existing practice for measuring and reporting acoustic exposures for focused ultrasound surgery, and the proposal is therefore made that a quantity that would be more satisfactory, from the viewpoints both of metrology and biophysical relevance, is the intensity spatially averaged over the area enclosed by the half-pressure-maximum contour in the focal plane, as determined under linear conditions, provisionally denoted as ISAL.

Optimum acoustic frequency for focused ultrasound surgery

A model is described that enables calculation of ultrasound lesioning rate (inverse of time to achieve a threshold lesion in the absence of thermal redistribution) as a function of acoustic frequency, tissue penetration depth, d, attenuation coefficient at specific frequency, mu, and power of dependence of attenuation on frequency, n. Two acoustic power conditions are considered: unlimited power, and power limited by the material properties of the transducer and the constraint that its dimensions be scaled to tissue penetration depth. Optimum frequencies for these two conditions are found to be, respectively, [(2 + n)/n mu d]1/n and [(3 - n)/n mu d]1/n. The tissue path attenuation, for both conditions, is independent of frequency, with a value of approximately 10 dB. Values of predicted lesioning rates under optimum frequency conditions are presented, and the likely constraints imposed by cavitation and propagation nonlinearity are considered.

Effect of blood perfusion on the ablation of liver parenchyma with high-intensity focused ultrasound

This paper discusses the effect of blood perfusion on the ablation of rat liver tissue with high-intensity focused ultrasound (HIFU). For this study a practical method has been developed, in which the liver blood flow can be reduced by ligation of the hepatic artery and portal vein. During the treatment the rat liver was mobilized out of the abdomen and the blood flow was measured using both the radioactive microsphere method and a laser Doppler blood-flow monitor. The results show that the hepatic blood flow was about 23 ml/100 g min-1 via the hepatic artery and about 227 ml/100 g min-1 via the portal vein. The total liver blood flow was reduced by 98% when both the hepatic artery and portal vein were ligated. Comparative lesions were made on the same liver lobes of rats with both normal and reduced blood flow using a focused ultrasound beam of 1.7 MHz, 67-425 W cm-2 spatially averaged focal intensity ISAL and 2-20 s exposure duration. A marked difference has been found between the lesion dimensions obtained with normal blood flow and that with reduced blood flow. For exposures at 169 W cm-2 the lesion diameter with normal blood flow was reduced by 14% for 3 s exposure duration compared to that obtained with both hepatic artery and portal vein ligated, while the reduction was more than 20% for longer durations.

Histological changes in rat liver tumours treated with high-intensity focused ultrasound

This paper reports the histological changes found in rat liver tumours treated with high-intensity focused ultrasound. HSN fibrosarcoma, implanted subcapsularly in the livers of CBH rats, were treated using an array of ultrasound exposures. At predetermined times following treatment, the rats were sacrificed and tissue specimens were examined histologically. Evident tissue damage was confined to regions that had been given high ultrasound exposures. Within these regions ("lesions") there was no evidence of intact cells whereas in the sharply demarcated surrounding tissue there was no evidence of cell damage. Where individual ultrasound lesions had been placed in sufficiently close proximity, there was correspondingly continuous and complete cell destruction. There is suggestive evidence that tissue damage may arise through two different mechanisms: direct, primarily thermal, damage and indirect damage resulting from compromised blood supply. Under the same exposure conditions, normal liver cells appear to lose their morphological structure more readily than do tumour cells.

Low urinary chiro-inositol excretion in non-insulin-dependent diabetes mellitus

BACKGROUND AND METHODS

Inositol is a major component of the intracellular mediators of insulin action. To investigate the possible role of altered inositol metabolism in non-insulin-dependent diabetes mellitus (NIDDM), we used gas chromatography and mass spectrometry to measure the myo-inositol and chiro-inositol content of urine specimens from normal subjects and patients with NIDDM: The study subjects were whites, blacks, and Pima Indians. The type of inositol and its concentration in insulin-mediator preparations from muscle-biopsy specimens from normal subjects and diabetic patients were also determined.

RESULTS

The urinary excretion of chiro-inositol was much lower in the patients with NIDDM (mean [+/- SE], 1.8 +/- 0.8 mumol per day) than in the normal subjects (mean, 84.9 +/- 26.9 mumol per day; P less than 0.01). In contrast, the mean urinary myo-inositol excretion was higher in the diabetic patients than in the normal subjects (444 +/- 135 vs. 176 +/- 46 mumol per day; P less than 0.05). There was no correlation between chiro-inositol excretion and the age, sex, or weight of the diabetic patients, nor was there any correlation between urinary chiro-inositol and myo-inositol excretion in either group. The results were similar in a primate model of NIDDM, and chiro-inositol excretion was decreased to a lesser extent in animals with prediabetic insulin resistance. chiro-Inositol was undetectable in insulin-mediator preparations from muscle-biopsy samples obtained from patients with NIDDM: Similar preparations from normal subjects contained substantial amounts of chiro-inositol. Furthermore, the chiro-inositol content of such preparations increased after the administration of insulin during euglycemic-hyperinsulinemic-clamp studies in normal subjects but not in patients with NIDDM:

CONCLUSIONS

NIDDM is associated with decreased chiro-inositol excretion and decreased chiro-inositol content in muscle. These abnormalities seem to reflect the presence of insulin resistance in NIDDM:

Performance criteria for quantitative ultrasonography and image parameterisation

For the purpose of assessing and comparing the practical performance of various specific approaches to quantitative tissue characterisation, three sets of performance criteria are proposed, relating respectively to contrast resolution, spatial resolution, and speed of presentation. In each case numerical performance targets are suggested: in particular that spatial resolution should preferably be within a linear factor of three of the best achievable anatomical resolution of the associated imaging techniques and that presentation speed should be 'real time' (i.e. about 10 Hz). In the light of these criteria and performance targets the main existing approaches to ultrasonic tissue characterisation are then considered. These are classified in two groups: first those approaches based on measurements of bulk properties of tissues and secondly those related to parameters of the structural organisation of tissues. Examination of available evidence suggests that the latter group are more promising than the former. Finally it is argued that ultrasonic methods of tissue characterisation have substantial practical potential but that the realisation of such potential is contingent on achieving consensus on choice of a single, optimised and generally applicable approach that would carry with it the linked benefits of industrial standardisation and broad sharing of clinical experience.

Damage to the hippocampal formation in rats selectively impairs the ability to learn cue relationships

We assessed the contribution of the hippocampal formation to performance in tasks that require rats to respond to a relationship between discriminative stimuli. The first experiment employed a nonmatching-to-sample procedure in a Y-maze. Three pairs of boxes were used which differed in brightness of the walls and in the odors that they contained. The rats were trained prior to receiving kainic acid and colchicine-induced damage to the hippocampal formation or electrolytic damage to the amygdala. After surgery all rats performed the nonmatching-to-sample task accurately if both brightness and odor cues were present in the sample and choice boxes or if the boxes contained either visual cues alone or odor cues alone. If the available cue modality was different in sample and choice boxes, then the amygdala-damaged, but not the hippocampal-damaged, rats performed accurately. In the second experiment control rats or rats with hippocampal formation damage were trained postoperatively in a conditional black/white discrimination task in a Y-maze. Only the control group successfully learned to select the white arm if the start box was illuminated and the black arm if the start box was dark. Subsequently, both groups learned a simple black/white discrimination. The same rats were tested in the hidden platform version of the Morris water task and only the control group learned to swim accurately to the goal. Both groups learned to swim accurately to a visible black platform. The results are consistent with the notion that the hippocampal formation is essential to learning that involves control exerted by a configural relationship among cues, independently of the spatial or conditional requirements of tasks.

Application of Fourier analysis to clinical study of patterns of tissue movement

An analysis is made of the kinetics of human liver parenchyma in response to mechanical impulses arising in the heart and aorta, and the results are applied to predicting the time course of the correlation between two time-separated A-scans derived from various regions of the liver. Such predictions are found to correspond well with data derived clinically, both from volunteers and from patients with liver metastases, using a commercial, real-time sector scanner. On the basis of Fourier spectral features of the clinically derived correlation patterns, a clear quantitative separation was demonstrated between the kinetic response of three classes of tissue: normal liver in volunteers, metastatic deposits in liver of cancer patients, and histologically normal liver regions in the same patients.

Ultrasonic study of in vivo kinetic characteristics of human tissues

A method is described for quantifying tissue movement in vivo from the computation of correlation coefficient between pairs of A-scans with appropriate time separation. The method yields quantifiable and repeatable secondary patterns of soft tissue movement in response to primary cardiac movement in a given subject, shows consistently different results as between normal livers and a variety of abdominal tumours, and is sensitive to either progress or therapeutically-induced regression of malignant disease. While the results reported here have been obtained using somewhat simple and crude equipment, the method is well suited to implementation on a commercial real-time scanner.

Wakefulness during cesarean section after anesthetic induction with ketamine, thiopental, or ketamine and thiopental combined

Thirty-six pregnant women (ASA class I or II) at term who underwent general anesthesia and cesarean section received either ketamine, 1 mg/kg (n = 12); thiopental, 4 mg/kg (n = 13); or a combination of ketamine, 0.5 mg/kg, and thiopental, 2 mg/kg (n = 11). A blood pressure cuff inflated to 250 mm Hg isolated one arm from the effects of succinylcholine so that awareness during anesthesia could be assessed by asking the patient to move her hand. Although only one patient receiving ketamine responded to commands during anesthesia, 46% of patients receiving either thiopental or the combination responded to commands intraoperatively. No patient hallucinated, the incidence of dreams was low (11%), and no postoperative dysphoria was noted. Three patients (8%) had postoperative recall of intraoperative awareness; one had received thiopental and two the combination. Maternal intraoperative cardiovascular responses among the groups were similar, as were umbilical blood gas values, newborn Apgar scores, and neonatal neurobehavioral test scores at 4 and 24 hr. Ketamine more effectively blocked maternal responsiveness to commands and strong stimuli during the first few minutes after anesthetic induction for cesarean section than did thiopental or a combination of thiopental and ketamine, each at a lower dose.

Subharmonic emission as an indicator of ultrasonically-induced biological damage

This paper describes work in which subharmonic emissions from ultrasonically irradiated biological samples are integrated over time, and the resultant signal (which is believed to be indicative of cavitation activity) is found to correlate well with the extent of cellular damage. Specifically, three studies have been carried out, in which the subharmonic energy emitted from suspension cultures of V79 cells is integrated during exposure to 1 MHz ultrasound. The effect of raised ambient pressure and sample rotation speed on the occurrence of cavitation, and of cavitation related cell death, have been investigated. Use of the subharmonic emission technique has also yielded additional evidence for the occurrence of an ultrasonically induced mechanism for damage that is neither thermal nor cavitational in origin, in experiments where cells are exposed to ultrasound whilst being held at an elevated temperature (43 degrees C). The potential of the use of subharmonic emission monitoring as a quantitative predictor of ultrasonically induced biological damage, both in vitro and in vivo, is discussed.